Jump to content
Zelandeth

Zel's Motoring Adventures...Jag, Citroen, Mercedes & AC Model 70 - 24/01 - Self Repairing Faults.

Recommended Posts

You need a thread gauge to check what it is as I'm going to be totally unhelpful and ask if it's British Cycle Thread.

Logically, can you get hold of old Fiat 500 drums as they will fit the pcd of the original half shafts, it's just if they will fit over the shoes etc.

 

Share this post


Link to post
Share on other sites
8 minutes ago, busmansholiday said:

Logically, can you get hold of old Fiat 500 drums as they will fit the pcd of the original half shafts, it's just if they will fit over the shoes etc.

 

it IS a fiat 500 Hub (AFAIK the brake drums does not really come into it at this point because the studs screw into the hub not the drum right?)

its just been drilled with 4 extra holes in god knows what for 4x100 wheels

(if only I had access to the Model 70 technical drawings! I know who they are with, but good luck getting said person to scan em all in! I may press the issue anyway)

 

Share this post


Link to post
Share on other sites

The drum at most would need the holes drilled out slightly larger... that's hardly the end of the world.

The problem using the original Fiat bolt pattern though is that it won't match the wheel...and as far as I'm aware, 10" wheels in the required PCD do not exist.  So I'd need to switch to 12" wheels.  Which I really would rather not do.

Share this post


Link to post
Share on other sites
8 minutes ago, Zelandeth said:

So I'd need to switch to 12" wheels.  Which I really would rather not do.

another problem with that would be finding a 12 inch wheel with the right offset

otherwise your going to have problems with the front wheel being off set to one side by too much!

Share this post


Link to post
Share on other sites

I wasn't expecting  normal at all !   I think you will find that Whit and BSF  generally, though not always, use the same size hex. heads. .

My logic was this:  it would be better to use a coarser thread than UNF into the hub, as it would be more suited to the cast material.  In imperial threads the options would be UNC, Whit or BSF.  Practically the whole UK/US motor industry was standardised on UNC/UNF by the 1950s.  BSF and Whit were obsolete by then, but were used on earlier British cars, and it is quite possible that AC would have had BSF tooling in stock.  In fact BSF at 20 tpi might be preferable in a relatively thin hub flange than UNC at 16tpi.  Looking at Zel's old stud it does not look as coarse as 16tpi on the short end, but might possibly be 20tpi, hence BSF.

If you have found Whit/BSF size heads on an engine  bracket, I bet the threads are BSF and that would tend to confirm things.  I think that makes sense - maybe someone else could comment?

Share this post


Link to post
Share on other sites
20 hours ago, Zelandeth said:

[] Temperature probe reading nonsense (see 160C reading above).

I can't help with the threads, but I should be able to with the temperature probe seeing as I've worked in that industry for years. Do you know what type it is? I.e. thermocouple (voltage) or a resistance type. The former is generally more robust, but involves a more complex measurement circuit. You would be able to tell by shorting out the probe terminals - a thermocouple system will read ambient temperature (assuming working correctly) but a resistance system will read either full scale high or low depending on whether NTC or PTC.

I'm finding this fascinating, even more than the vehicles!

Share this post


Link to post
Share on other sites
26 minutes ago, mat_the_cat said:

I can't help with the threads, but I should be able to with the temperature probe seeing as I've worked in that industry for years. Do you know what type it is? I.e. thermocouple (voltage) or a resistance type. The former is generally more robust, but involves a more complex measurement circuit. You would be able to tell by shorting out the probe terminals - a thermocouple system will read ambient temperature (assuming working correctly) but a resistance system will read either full scale high or low depending on whether NTC or PTC.

I'm finding this fascinating, even more than the vehicles!

I haven't done too much investigation on that yet - disconnecting the probe for it drops the reported temperature down to around 80C.  I have a sneaking feeling that there's a missing or way out of whack reference voltage rail somewhere which is probably what's throwing a whole load of the measurements off.  I've not even looked at the analogue front end side of things yet.

At least a couple of the boards are liberally scattered with tantalum decoupling capacitors as well...these are famously unreliable and could well be leaky and dragging one or more of the supply rails down.  Given the record of these things I may well just replace these on sight in the interests of future proofing/long-term reliability.  If it fixes any issues along the way it's a bonus.

Share this post


Link to post
Share on other sites
6 hours ago, Zelandeth said:

Fluffing Hell...this is the problem that just keeps on giving.

The thread in the hubs that the studs screw into on the Invacar is NOT 3/8" UNF apparently.

IMG_20191121_164117.thumb.jpg.72e1b844e8071d06ad5976c8e2c6877e.jpg

Really wish I could just find another hub at this point and be done with it.

I'd second the BSF hypothesis, got to be worth a shot; the thread damage certainly looks like it's gone into a thread the same diameter and smaller TPI/greater pitch.

Share this post


Link to post
Share on other sites

Well I'll order some 3/8" BSF bolts.  For the sake of a few quid it's worth a shot.

If they don't immediately screw in perfectly I'm pulling the hub off.

It will then be sent over to the fabricator who made me the fuel tank with the instruction to do the machining work necessary to make it use sensible wheel nuts.  Whether that means machining a land in the back surface of the hub to allow splined studs to be used or drilling and tapping it for metric wheel bolts...to be honest I've little interest in...this is one of those things which I just want to work!

Had kind of hoped a spare hub might have surfaced by now, sadly not to be it seems.

There are a million things I would rather be doing with this car than faffing around with bloody wheel studs three months in.  Would really like to be able to drive it again now please...

Share this post


Link to post
Share on other sites
39 minutes ago, Zelandeth said:

Well I'll order some 3/8" BSF bolts.  For the sake of a few quid it's worth a shot.

 

I just hope the thread(s) in the hub have not been mangled by the 3/8th UNF bolt

39 minutes ago, Zelandeth said:

There are a million things I would rather be doing with this car than faffing around with bloody wheel studs three months in.  Would really like to be able to drive it again now please...

you and me both! Id of really have liked to have made more progress with REV then I have so far, but sadly things just did not work out in my favour

still hoping I can get the fuel tank removed sometime before the main "fix it" day so I can get a head start on that at least! (as I dont want to have everything ready to go on REV only to be fouled up by the fuel tank)

as I think the fuel tank on REV is the only "major" component that need/may need serious specialist outside attention, the rest is thankfully fairly minor stuff, hopefully! famous last words....

Share this post


Link to post
Share on other sites

Argh!

I'm coming down with a cold.  Not unexpected as everyone else in the house has had it.

This has made getting to sleep even harder than usual.  Just after 0600 I was finally starting to feel restful and that I had some hope of dozing off at some point soonish.  Right up to the point where I coughed.

Now I have the goddamn hiccups.  Which are doubly fun with an already sore as hell throat and sore chest because I've been coughing all day.

Friday is going to be a long day I fear.

Share this post


Link to post
Share on other sites

After what should have been an hour or two round trip taking nearly the whole afternoon because of sodding traffic, have a correct replacement part for the Sun 1215 and a spare for the future.

IMG_20191122_161426.thumb.jpg.e530c7fdce0d3dd62e9ab6f750046f4a.jpg

Apparently the seller does indeed have about a thousand of them, so worth keeping an eye on their page LBF if they offer delivery.  I never checked that as they were just 15 miles or so down the road.

Will get that installed shortly.

Share this post


Link to post
Share on other sites
27 minutes ago, Zelandeth said:

After what should have been an hour or two round trip taking nearly the whole afternoon because of sodding traffic, have a correct replacement part for the Sun 1215 and a spare for the future.

IMG_20191122_161426.thumb.jpg.e530c7fdce0d3dd62e9ab6f750046f4a.jpg

Apparently the seller does indeed have about a thousand of them, so worth keeping an eye on their page LBF if they offer delivery.  I never checked that as they were just 15 miles or so down the road.

Will get that installed shortly.

ah awesome that they were close enough to be picked up personally much reduced risk of them getting smashed! :) 

they do indeed offer delivery, or did for the 1 listing they had

ill keep an eye out on their ebay page, maybe depending on if they are willing to do a bulk discount, I could see myself picking up an entire case of them at some point in time :) 

I wonder where they came from or what they were ordered for, as mentioned previously 30W T12s are very uncommon here and most people dont even know they existed

 

its worth noting that they are very  late GTE tubes, of a transitional design, they have the 1980s GTE etch, but later mid 1990s stepped end cap design, the date code comes back as Aug 1993 if im reading it correctly :) 

(by 1993 I think osram had already acquired GTEs lighting division in the US)

 

it will be interesting to see if now with proper rapid start tubes, you get a proper rapid start fade in as the cathodes warm up to temperature and the striking voltage drops over a second or so :) (im not surprised the F30T8 started instantly as it would of been cold starting due to the lack of proper cathode heating)

 

on that note, due to the low cathode heating voltage of 3.6V its important you make sure the socket contacts are clean and making good contact!

Share this post


Link to post
Share on other sites

Worth dropping the seller a question through eBay asking if they're planning on listing any more.

New lamp was fitted without incident.  Still instant starts... suspect this may be one of those ballasts which is a bit brutal about starting.

IMG_20191122_171842.thumb.jpg.18765e453ab9c5a0a2b64eb82f3ff06e.jpg

Realised that one thing I didn't check last time I had this opened up was whether the back of the diffuser was clean...not really was the answer.

IMG_20191122_171830.thumb.jpg.2ade7af7a6510cd7dd991a069bda53ae.jpg

Everything back together.

IMG_20191122_172702.thumb.jpg.d1781e2acfe82aa6a863881265bff53d.jpg

Figured for those interested in the procedure in setting this thing up I'd run through it without missing a bunch of steps, as previously I'd very much abbreviated it.

This isn't a full user guide...but is a quick run through of the real basics from what I remember of using the one a mate had about 20 years ago and what I've seen messing around with this one. 

Hopefully this will demystify all those buttons a bit.

When first powered on the machine shows a message informing you that it has started its warmup phase and gives a countdown to when it will be ready to use.

IMG_20191121_183451.thumb.jpg.172ac6bdd6eabb78619617651ff48bb5.jpg

You can bypass this delay at any point by pressing #, but there's obviously a greater chance of the accuracy of the machine may drift as it warms up.  The fifteen minute delay helps ensure that everything is stable before you put it into use.

The # button basically functions as the "next page" control throughout.

IMG_20191122_172827.thumb.jpg.52abceb5f662a3445a69f100df50c70d.jpg

When the countdown runs out it waits for you to press # to continue before it will move on to the self test/calibration screen.

IMG_20191121_183747.thumb.jpg.16ab6c78a15dee5533a3f447e69b02e3.jpg

This takes a minute or so to run through...and obviously has a few errors reported in the case of my machine... hopefully these will disappear as time goes on and I work through things.

IMG_20191121_183903.thumb.jpg.7da8ed19d21a7b78fb5178bcd084bc75.jpg

Next page is the program setup screen where things start to get a little more interesting.

IMG_20191121_183914.thumb.jpg.ade71a0168753bf714478f0c40e863c4.jpg

The "set ignition selector" relates to two modes that the ignition side of things can run in.  There's a table in the operator's manual telling you which cars which setting should be used with.

This is selected using this button.

IMG_20191122_172739.thumb.jpg.fc3c71938b943796b1d163215d986ca9.jpg

Shown above in mode 1, and below in mode 2.  Yes, this is a bit of an excuse to show off the flipdot indicators...even if they are a bit grubby at this stage.

IMG_20191122_172748.thumb.jpg.f45d4ff406bba3c72331f09a7b8d08a3.jpg

"Set 2 or 4 cycle"  is asking you to select whether the engine is a two or four stroke.  There's a dedicated button for this, which like the ignition selector has an indicator built into the button itself.

IMG_20191122_172752.thumb.jpg.52056b21549dd7b58c7a69ff5ac6de7a.jpg

Self explanatory really...4 for a four stroke and 2 for a two stroke.

IMG_20191122_172808.thumb.jpg.47c98fc22af30836757809eb61b23842.jpg

The number of cylinders is then set using the left of the three buttons below.  These have different functions in different program modes hence having several legends, it's less confusing than it initially looks.

IMG_20191122_172819.thumb.jpg.b593ac1231daea5d21ed2f5c4a7a3154.jpg

The selection starts at 0 by default, and pressing the button cycles through 2, 3, 4, 5, 6, 8, 10, 12 then loops back to 2.

The last thing on this section is the timing offset.  This is only needed I believe where the car uses a magnetic pickup to fire the ignition, this is usually offset a few degrees before or after TDC.  You need to dial this in here.

Pressing "number select" initially changes the sign to + or - to reflect whether the offset is before or after TDC, then "cursor advance" moves to the first digit, with "number select" used to advance the number.  This process is repeated until you've dialled in the correct offset.

The screen below is an example which would have been used on my old Saab from memory, you can see the cursor showing which digit is being entered.

IMG_20191121_183939.thumb.jpg.96d9d34ef4bbb7702f758d87d9a2dbe4.jpg

Once you have advanced to the last digit it will tell you to press # to the next page.  It won't let you proceed if there are things you've missed.

IMG_20191121_183951.thumb.jpg.e912020c60de709c29e6fb9985ca3fe7.jpg

This then brings you up to the "Cranking/Pinpoint Tests" page.

IMG_20191121_184007.thumb.jpg.b71d2d36488bc3358628ff878a920dee.jpg

This gives you quite a bit of information on what's going on.  However this is only half the information it can show you.  An additional page is accessible using the "short" button on the control panel.  This appears to indicate "short-cut" rather than that it shorts anything out to kill the ignition system or anything.

Here it's shown pressed, hence the vivid orange indicator shown.

1392299547_IMG_20191111_2144182.thumb.jpg.eb76128e37a5d5c447fbeef6850a0c49.jpg

All of the buttons - even those which are purely momentary - have the indicators in them.  Utterly unnecessary, but a nice touch.

This screen gives you some really quite clever diagnostic information.

IMG_20191121_184042.thumb.jpg.913c46d66d340ce063ce3ebc47681856.jpg

This shows you the difference in engine speed, starter motor current draw as the engine spins over each cylinder.  This can be helpful in showing if one or more cylinders has a significantly lower compression ratio than the others. 

You might need to actually stop the engine from starting to get solid data from this test, and there's a control to disable the ignition system labelled as "engine kill."

335446540_IMG_20191111_2144432.thumb.jpg.068c685747dc6a398144ecb8f9944b83.jpg

Pressing this toggles the kill, and when it's enabled a flashing "engine kill" warning is shown on the display to warn the user.  Having this feature on hand is obviously useful from a safety perspective as well.

The "Short" button latches, so pressing it again will drop you back to the Cranking/pinpoint Tests page.

Once you're done with that, pressing # will advance you to the main running test page.

IMG_20191121_184058.thumb.jpg.44307552e0f357de41ffc98a9aa24854.jpg

This shows you pretty much everything you need to know.  The displays look to update pretty rapidly, at least a few times a second.  If wanted, you can pause the data on screen with the "Display Hold" button.  This is directly below the # button.

IMG_20191122_172827.thumb.jpg.52abceb5f662a3445a69f100df50c70d.jpg

When this is enabled a "hold" message flashes at the upper right of the screen to warn the user that live data isn't being shown.

A useful feature of this as well is that in the main screen above, when the display hold control is released, the original data is left in the screen with a new column being put up for the live data.  This allows you two "old" readings to be shown along with the live data.  This could be really useful if you're making small tweaks and wanting to double check what effect it's had.

The below display shows a "full" page with two columns of held data shown.

IMG_20191120_174821.thumb.jpg.482c8c1e3fe2d733a7dbbb8443f8e4ce.jpg

The live data is always shown on the leftmost column.

That's as far into the running of this unit as I've gone...but it gives you a basic rundown of how the computer works.  Shows how it does a pretty good job of guiding you through everything...which in the mid 80s really wasn't a given!

Probably the most daunting looking controls relate to the scope...though I've never really done enough work with that to be able to talk through it from memory.

IMG_20191122_172720.thumb.jpg.9551056673494b0632eac58c145c4a69.jpg

The Short button being grouped here rather than with the computer controls is just to keep you on your toes.

I'll try someday to write a bit of a how to for this too...I'll need to learn to drive it a bit better first though. 

Likewise some of the advanced features of the computer...there's a whole additional layer in there I think.

For the sake of convenience there's a remote control which duplicates a number of buttons from the front panel to make life easier for the technician.  #, Display Hold, Short and Engine Kill being those controls.

IMG_20191122_173015.thumb.jpg.d4361a0a4ce97584dd6bfad523f41ad6.jpg

The "Print" button would trigger the optional printer.  No timestamps or anything, it would just literally print a copy of what's shown on the screen.  Sadly I don't have the printer, though I do have the interface card (found in the base cabinet) should I ever come across one.

 

Probably horribly tedious to most of you, but hopefully it's vaguely interesting to you if you're into old tech and want to see what would be happening when you're blindly mashing buttons to see what makes it tick.

Any questions, let me know.

Share this post


Link to post
Share on other sites
7 minutes ago, Zelandeth said:

Probably horribly tedious to most of you, but hopefully it's vaguely interesting to you if you're into old tech and want to see what would be happening when you're blindly mashing buttons to see what makes it tick.

Tedious?! It's made my Friday night...beats the Graham Norton show or whatever is on the TV. Thanks for the photos and the detail :-)

Share this post


Link to post
Share on other sites

I enjoyed reading the detailed write up very much as well :) 

its interesting to hear it only goes down to 2 cylinders, Poor @egg cant have his Mk12 diagnosed/tested by it! 

unless that would be done using the "0" cylinder setting?

also im curious how would/could a rotary engined car be hooked up to it? or what about a wasted spark ignition system like in a 2CV?

Share this post


Link to post
Share on other sites
13 minutes ago, timolloyd said:

I’m really enjoying this, thank you. Keep up the good work!

 

13 minutes ago, mat_the_cat said:

Tedious?! It's made my Friday night...beats the Graham Norton show or whatever is on the TV. Thanks for the photos and the detail :-)

Thanks folks, nice to know I'm not being totally boring!  I just can't quite get my head past what a pleasing thing it just is.  You just don't get industrial equipment with this sort of visual flair these days.

Really do need to clean the control panel and the buttons though.  The inside of the buttons is quite dusty too...so I suspect that getting those properly clean may involve quite a bit of work.

On the plus side, the matching mechanism is on the upper surface of the casings, so I should be able to get the ones which are currently sticking to cut it out and behave themselves without too much hassle.

I'll need to see what I can do about the paintwork on the case... there's surface rust speckling quite a lot of it, so a respray is probably the only long term solution...suspect that's a few years down the line though!

Share this post


Link to post
Share on other sites
4 minutes ago, Zelandeth said:

Thanks folks, nice to know I'm not being totally boring!

It almost certainly is to the average person in the street, but to a small subset of the population (possibly in a majority on this forum) it's just ace! I completely get you with the old tech thing - before everything got cheapened down to 'just good enough'.

Share this post


Link to post
Share on other sites

Because I'm me and find them far more interesting than I probably should, here are a couple of additional photos of the ridiculously overcomplicated status indicators built into the buttons.

It surprises me that they went to the lengths of building them into even just the momentary controls.  You never actually *see* this one as the control is actually latched on software...the orange announciator in the button is normally hidden by your finger.

IMG-20191123-181508.jpg

The actual indicator that this is active is a message that flashes at the lower right hand corner of the screen.

IMG-20191123-181138-2.jpg

There is apparently a volts/ohms measurement capacity in there somewhere (which I've yet to figure out how to access), which is switched between the two modes using this control.  Here it is in volts mode...

IMG-20191123-181448.jpg

 

...and ohms mode.

url%5D

 

Just surprises me this wasn't just done either on screen or using a status LED next to the control.  I remember looking at this sort of control when I was building a power supply a few years back, and these things were *expensive* - even basic ones without legends like this.  "We spared no expense" seems to be a running theme with this machine.

I've got a slightly more sane (though still offset) temperature reading now I've actually got the thermocouple plugged into it rather than a hall effect sensor!

I wanted to have a look at all the analogue cards to check for any additional socketed components, dirty contacts or dry joints.

Started out with the volts/ohms board as I know there are issues with that subsystem.

IMG-20191123-185919.jpg

Had a brief "Ah ha!" moment when I spotted that toasty looking resistor...but checking it shows it to measure precisely the value that's stamped on the side of it.  Nothing else obviously amiss.

The next board is the trigger control board.

IMG-20191123-190205.jpg

This is quite important in that what it does is essentially listen for the ignition pulse firing on cylinder number 1, as that is the timing reference to which everything on the machine is slaved.  Nothing amiss here that I can see.

Unsurprisingly, the next board along from that is the main timing board - this basically keeps everything in sync with the signal tracked by the trigger control board.

IMG-20191123-190344.jpg

One of the more densely packed boards.

I initially thought that the next board (labelled "AMP" on the card cage) was going to handle a lot of signal amplification...but it actually appears to be the signal processing for the amps and temperature sensors.

IMG-20191123-190509.jpg

This board does have a couple of dry joints that I'll give a tickle with the soldering iron tomorrow.

"CAL" is the next one, which I'm assuming given the precense of several relays, physically connects loads of known values across the inputs to undertake the calibration self test.

IMG-20191123-190704.jpg

Again some of the soldering isn't great looking, but I couldn't actually see any dry joints...I may well reflow some of the heavier connections though as they could be better.

The fact that the only systems which are consistently failing the self calibration are the HC and CO meters is one of the reasons I want to have a really good look at the wiring from the I/O backplane to the sockets at the end of the boom.  

Speaking of I/O, that's what the next board is tasked with dealing with.

IMG-20191123-190821.jpg

Nothing wrong with this one that I could see.

Next up is the vertical pre-amplifier board, I believe this relates to the scope.

IMG-20191123-190918.jpg

Quite obvious from the lovely old school hand routed traces that this one and the trigger control board are quite a bit older in design to the majority, though the date codes show they were actually made at the same time as the others.

"Logic Board No. 2" is next...though I don't recall seeing a number 1 anywhere!

IMG-20191123-191024.jpg

I'm guessing a bit, but based on the hardware present that this is just handling some low level buffering or such like they didn't have room for in the main computer cage.

No signs of trouble anyway.

Finally we have an identical pair of cards containing quite beefy deflection amplifiers to drive the CRT (one card handles horizontal, the other vertical).

IMG-20191123-191157.jpg

All of these boards could do with a good clean, as do the digital boards (which I'll grab proper photos of soon too) due to the close proximity of the cooling fan.  Shame Sun didn't feel it worthwhile to fit a filter to it.

So nothing nothing obviously amiss there, aside from one resistor which has got a bit warm at some point and one capacitor on the amp/temp board that's got dry joints.  I really did want to get them all out for a proper check over though.  No socketed ICs or anything like that (which was responsible for the original display issue) in need of attention, but it was worth checking.

Looks like I might actually get a few hours free tomorrow afternoon, if so I'll hopefully get a bit more stuck into trying to work out what's going on with the faults.  

The biggest irritation there really is that there don't seem to be many labelled test points, which would make checking to see if all the power supply rails are present and correct (there are a load of them!) a lot easier.  Obviously given the card based construction it's a bit tricky to probe a lot of the machine when it's running as the cards are quite tightly packed together.

The other thing I wanted to check these cards for was whether they were hiding any more tantalum capacitors like I've seen on at least one or two of the digital boards, as once I've ascertained how many of them there are they will be getting replaced on mass.  Wouldn't surprise me if that alone sorted a lot of the issues based on prior experience.

Share this post


Link to post
Share on other sites

very neat stuff!

id still be a bit weary of that toasty looking resistor, and would look at replacing it,

it might measure fine when cold, but I could see its value drifting/changing as it warms up given how sad it looks

(plus knowing my luck, id have everything working, and just as I get it all buttoned up that resistor would actually fail on me!)

Share this post


Link to post
Share on other sites
4 hours ago, LightBulbFun said:

very neat stuff!

id still be a bit weary of that toasty looking resistor, and would look at replacing it,

it might measure fine when cold, but I could see its value drifting/changing as it warms up given how sad it looks

(plus knowing my luck, id have everything working, and just as I get it all buttoned up that resistor would actually fail on me!)

Access really isn't an issue on this thing.  Getting access to the computer takes about 90 seconds.  Maybe double that to get the full height digital cards out. 

It is a somewhat high power resistor, so I'm not discounting the discolouration as just being the results of 30+ years of use.  Not that unusual to see things like that in televisions from this era.  As I think I do have a suitable replacement in stock though I will probably look to get it swapped out though once we've got any suspect caps changed.

Does make me wish I had a set of schematics though so I could see what it's doing.  It's a bit tricky to reverse engineer as a lot of connections just disappear into the backplane connectors and off to goodness only knows where.

Share this post


Link to post
Share on other sites

Today was the day to get all the digital cards out for a check over and to get everything reseated.

So here are the digital boards, from left to right.

"CRT" - This is responsible for taking the data from the computer and converting it into a composite video signal which is fed to the monitor.  

IMG-20191124-164217.jpg

"MUX" - Handles all the analogue to digital conversion, signal processing and such like.  Initially I thought "oh my god bodge wires" when I saw this, before realising those wires are all shielded coax, so they have just decided it's a more reliable way of getting a clean signal across the board than using PCB traces.  Even if it does look a bit shonky.

IMG-20191124-163943.jpg

The whole machine is astonishingly free of bodge wires actually...especially for a design from the late 70s where they usually would find *something* after the board's had gone to be made...

Lovely white ceramic package on the ADC.

"I/O" - No great surprise, does most of the heavy lifting with regards to the actual I/O side of things.

IMG-20191124-163824.jpg

"CPU" - Unsurprisingly, contains the CPU and the 64kB of RAM it makes use of.

IMG-20191124-163543.jpg

"MEM1" - Basically all the ROM.  Interesting to see that while these initially all look to be EPROMS, they're not.  While there are some, there are also a shedload of character generators.  My guess is they're using this to give greater control over the display without going to the lengths of full bitmap control.

IMG-20191124-163428.jpg

"PP" - Pre-Processor.  Not actually entirely sure what this does, though I have to assume basically just does some general housekeeping which we would normally expect to be handled directly by the CPU these days... purely a guess though.

IMG-20191124-162658.jpg

The EPROM here was losing its label, so a bit of black tape was applied to help keep the data safe.  

Probably the main reason I would love to find an actual service manual for this (VERY unlikely as Sun kept really quite tight control over) is that it would probably give me a really good breakdown of the actual system architecture - sadly there's a lot of hardware in here I've never worked with before, so there's a learning process involved.

All of the socketed components on these boards were reseated while I had them out, as I knew this had already sorted one problem.

Turns out that while it's not fixed everything (the gas analyser is still failing the self test), it has definitely helped.  Previously we had complete nonsense shown on the voltage readout.  Now however we seem to have sensible data shown.

IMG-20191124-202427.jpg

The column on the right is showing the data from when I had a car battery connected to the voltage measurement lead, the one on the left is with the leads shorted together.  Had to do that as it's smart enough to know when there's nothing connected and will just blank the display for that measurement.  Helpful in the real world...but slightly awkward during testing!

Not worrying too much about a 0.2V offset at zero for an instrument of this type, the reading with a load connected was spot on...multimeter was showing 12.23V.

Worth noting that we appear to have more sane readings on the vacuum gauge as well now, that was tending to wander around quite a bit at rest too.

Definitely progress.

Know this is repeating myself to some folks I've spoken to about this, but I figure it's worth mentioning one of my plans for this thing long term to the world at large.  One of the useful things about the monitor the computer is that it's simply a self-contained composite unit.  The signal from the computer to it is simply carried by a twisted pair of wires.  So it would be a truly trivial task to cut into that and introduce a switchable video source.

My intention here is to fit a small self contained computer (probably a Raspberry Pi because I know I can just throw Debian at it rather than having to muck around with it) somewhere in the case.  This would then allow me to use the monitor there to view manuals, data sheets, instructional videos etc in the garage on something a bit more user friendly than a tiny phone screen.  It's a really nice sharp screen so should do just fine.

I'll do doing nothing which cannot be reversed easily.  The only thing I'll need to fit to the outside of the case will be a switch to change video sources.  Luckily I won't even need to drill a hole for that as there's a convenient rubber bung by the remote control input for an option port...so I can just put a hole into that rubber bung rather than drilling a hole in the actual case.

IMG-20191124-170811.jpg

Just seems a really nice way to bring it functionally into the 21st century somewhat to help it perform the sort of tasks it was originally designed for.  Quite often I find myself in the garage with a wiring diagram of something open on my phone and getting really fed up with the screen turning off every five seconds...so having a fixed screen which I can't drop under the car will be most appreciated.

So that's what will be getting done to improve it in addition to the actual service and repair work.

Share this post


Link to post
Share on other sites
17 minutes ago, Zelandeth said:

I believe this is the point where I should cue the mad scientist manic laughter...

IMG_20191125_222203.thumb.jpg.86847e62b84208d473fc948a3da18763.jpg

Actually an order of magnitude clearer in person...my camera (unsurprisingly) isn't fond of taking pictures of an interlaced CRT display.

haha awesome :) 

its like that little black and white TV you have setup, but on another scale entirely :) 

Share this post


Link to post
Share on other sites

I wound up out in the garage earlier this evening digging some rubbish out the chest freezer at the back and when done figured it was about time I gave TPA a bit of a run.

I then figured I may as well set the camera recording...so have a fifteen minute ramble with bits of Invacar involved.

Apologies for it all being in portrait...I realised I'd done that after about five minutes and couldn't be bothered starting over. (You can't change it while recording...and I didn't want to have to faff around editing videos together for what was meant to be a quick ramble!).  Will make a point of getting that right next time.  Oh...and setting notifications to silent so the phone doesn't buzz at me while video is being recorded on it.

Share this post


Link to post
Share on other sites
7 hours ago, Zelandeth said:

I wound up out in the garage earlier this evening digging some rubbish out the chest freezer at the back and when done figured it was about time I gave TPA a bit of a run.

I then figured I may as well set the camera recording...so have a fifteen minute ramble with bits of Invacar involved.

Apologies for it all being in portrait...I realised I'd done that after about five minutes and couldn't be bothered starting over. (You can't change it while recording...and I didn't want to have to faff around editing videos together for what was meant to be a quick ramble!).  Will make a point of getting that right next time.  Oh...and setting notifications to silent so the phone doesn't buzz at me while video is being recorded on it.

I enjoyed the video very much :)  (apart from the fact its in portrait but you know that already)

nice to see TPA getting an engine run at least!, I wonder if it would be worth propping her up on stands, and then putting it into gear to give the pulleys a run, so the surfaces stay clean etc?

as for car phone mounts, have you tried talking to @dollywobbler about the kit he uses? given recording video in cars is literally his job at this point and he also has a Model 70 :)

(Btw to the previous post, whats the rez its running at? looks like 1024x768? looks surprisingly clear for composite video, but then again its only BW not colour)

Share this post


Link to post
Share on other sites

I'm not too worried about issues with the drive at the moment.  She's stored in a very dry well ventilated and reasonably warm garage so corrosion should not be an issue really.

Good question on the resolution.  Had to poke it over the network (that system doesn't usually even have a display attached) to check, but it defaults to 1024*768 so that's the most likely option.

The display is really surprisingly clear - and will be more so once I lock the thing into a greyscale colour mode as if should get rid of the noise on the image due to the colour content.  Don't imagine locking the RPi into a greyscale mode is hard.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By richardthestag
      Been a busy 6 months on my old Range Rover that I own 50/50 with Fathathastag
       
      Bit of background first..
       
      We bought it March 2015 just as genuine early Range Rovers were starting to get noticed. Alas not early enough that we could have got it for a couple of hundred quid. 
       
      The car had been owned for decades by a Land Rover enthusiast and this particular car retained a lot of features unique to pre 1973 Range Rovers. Sadly he died a few years back and the car was left outside the front of his house. 
       
      I spotted it on eBay and arranged with the owners widow to view. There were no bids and my offer was good enough to take the auction off.
       
      The engine had been part way through a top end strip down when work stopped, I had no idea even if the car would move. But rented a trailer and relocated it from Watford to North Devon where fathathastag has a barn suitable for storage.
       

       

       
      The project is on the right, we towed it into the field and pushed it into the barn

       
      In May 2015 I got to do an assessment of the car. body wise most outer panels were ok, the inner wings looked ok, it clearly needed some work but was unsure how much at this point. main objective was to see if the engine was a runner.
       

       

       

       

       
      Found that the gearbox and axles were original to the car, but the engine was from an earlyish SD1
       
      while the seat covers are not original some of the plastic kitkat seat coverings are underneath, the rear seat especially
       

       

       

       

       
      The head has some nasty corrosion very near the fire ring seal, 
       

       
      When I refitted the head one of the bolts tore the thread out. bastard but not entirely uncommon with the alloy blocked RV8
       

       
       
       
       
       
    • By richardthestag
      Hey folks
      new project, as you saw in the other thread I accidently persuaded fatha thestag to buy a 109 truck in relaxed state
      here is the walk around, let my mouth do the talking
       
    • By captain_70s
      Hullo,
       
      I'm a masochist from Leeds who is running two rusty, worn out Triumph Dolomites as my only transport in rural Aberdeenshire. You might recognise me from various other forums and Facebook groups. Realistically I need to buy a modern car of some sort, but instead I find myself looking at £300 Citroen BXs and Triumph Acclaims on Gumtree and thinking "yeah, that'd fit right in with the rest of the broken cars I can't afford".
       
      On to the cars, the main attraction being my 1976 1850HL "50 Shades of Yellow" that I bought for £850 and is currently my daily driver, here is a picture of it before I sanded off some surface rust and sprayed it badly in the wrong shade of yellow with rattle cans:
       

       
      Within a month of purchase I managed to plant it in to a steel fence backwards after a botched gear change on a wet roundabout and ruined the N/S rear wing, although judging by the other dent that's packed with filler it looks like somebody had already done the same. I also managed to destroy a halfshaft and one of my Sprint alloys (good for an extra 15hp) in the incident, so now it's sitting on it's original steelies but painted black (good for an extra 5hp).
       
      It's only broken down on me twice. once with some sort of fuel delivery related problem which may or may not have been an empty fuel tank and once when the thermostat jammed shut and it overheated and blew out some O-rings for the cooling system. It has recently developed a taste for coolant and oil which is rather annoying, although it's done 89,300 miles which is about 80,000 more miles than BL engineering is designed to last, I'm keeping my eye on eBay for replacement engines... 
      I tried to keep ahead of the rust a bit by rubbing down the arches and re-painting them, but apparently rattle can paint isn't great when you are spraying it at -5C, it also highlighted how although my car might have been Inca Yellow in 1976 it's now more of a "cat piss" sort of shade. So I ended up with the wrong shade of yellow which has rust coming back through after 5 weeks. Did I mention I'm incompetent?
       
      The other car is the first "classic" car I bought, so I can't bear to sell it. It's a '77 Dolomite 1300 and it cost £1400 (about £400 too much) and has been nothing but a pain in the arse:
       

       
      It looks much prettier (from 100 yards) but that's most due to the darker paintwork hiding the rust. It lives a mollycoddled life in my garage, where it somehow still manages to rust, and is utterly rubbish. 0-60 is measured on a calendar, top speed is 80ish but at that point it uses more oil than petrol, it rarely ventures over 50mph and if you encounter an incline of any sort you can kiss that sort of speed goodbye, along with about £20 of 20W50 as it vanishes out of the exhaust in the form of blue smoke.
       
      One of the PO's had clearly never heard of the term "oil change" so it developed into brown sludge that coated everything internally with the next owner(s) blissfully pouring fresh oil on top of it. This lasted until about 600 miles into my ownership when there was muffled "pop" from the engine bay and the car became a 3-cylinder. The cause was catastrophic wear to the top end causing a rocker arm to snap:
       

       
      As this was my first classic car I'd assumed it was supposed to sound like the engine was full of marbles, it wasn't.
       
      I put the engine back together with second hand bits declared it utterly fucked and promptly did another 5000 miles with it. After about 3500 of those miles the oil burning started, valve seals have gone so it's been relegated to my parent's garage as a backup car and something to take to local car shows as the 1850 is now embarrassingly ugly. I'm keeping my eye on eBay for replacement engines (deja vu, anybody?) Oh, I also recently reversed it into a parked Ford Fiesta and royally fucked up the rear bumper, rear panel and bootlid. Did I mention I'm incompetent?
       
      There have been two other cars in my life. My first car, a 2008 Toyota Yaris 1.0 an it's replacement a 2012 Corsa 1.4T. I didn't really want either of them, but it's a long story involving my parents and poor life choices. Ask if you want to hear it!
       
      So that's a brief summary of my current shite. If you want more pictures or details of anything do say as I've got photos of almost everything I'd done with the cars.
×
×
  • Create New...