JECS and Newbie!

[Lachlan]

Oh cripes I put my foot in it didn't I?!! LOL :)

I Most of my work involved the following:

dead unit arrives, open it up and have a good look. throw it in a acetone bath with
agitator (they were the easiest to clean off the lacquer as it was quite thin,  others
like the bosch units from memory had a thick gell coating that was very hard to remove).
then if it looked fine and most of the time the problems were burnt out tracks, I would
run it up on the custom jig and see if it ran, if it did then it was simply a case of
testing that it was ROUGHLY Calibrated, re-solder the whole board, re-laquer it and send
it off. you would not believe how many computers we got that were fine or just needed a
resolder. As far as 'electronicing' goes I would endevour to trace the problems and found
ground-outs and OC's inside the couple of magic IC's on the board, these I never 'cracked'
as the company's objective was not to waste time on the odd dificult to repair units, The
big CPU IC (DIL 60-odd pins with no identifiable numbers) was certainly dead a few times
and when I had the time I would try to investigate this chip but did not get a chance
often. we were not in the business of modification and performance and this 'exploration'
was low priority. OH and legally I cannot give out a lot of details of specifics that I
learned, due to the contract I signed. We did not get into code at all, a unit either
worked or it didn't.

Mainly the JECS units I worked on were the TURBO and non-turbo  nissan 4, 6 and Commodore
VL 6. these units were all v. similar.

I hope I have not left you JECS people too disappointed. Remember also that I have not
touched/thought about/fixed one of these since 94. I do remember it being a simple and
clean unit with nice signals and easy to find faults, though I knew 99.9% of them haveing
fixed so many, I got great joy out of getting a 'unfixable' unit out of the 'dead' box and
getting it going :) usually an out of range component or a dry joint that was difficult to
find.

regards,
Lachlan

> Date: Wed, 5 Sep 2001 18:27:56 +1000
> From: Christian Hack <christianh at pdd.edmi.com.au>
> Subject: Re: Digital Tach and Newbie!
>
> Don't go all quiet on us Lachlan! There are a few would be JECS hackers (lurkers)
> around and given there is next to no info available on them, I'm sure anything you can
> tell us would be appreciated. Everynow and then someone asks about them.
>
> Were you mainly just repairing them? Did you have schematics at all or did
> your repairs mainly involve replacing dried out electros, fixing bad solder joints
>  etc?

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