S-2000 processor board repairs

[Jim]

I have quite a few 502/ 504 boards that have similar failures. I am going to make a board tester, and troubleshoot these boards.  the main failure has to do with the door optics circuit which gives the failure codes such as, M Door Open,  MB Door Open,  and the Please close the main Door, after you hold the test button 3/5/seconds. (as determined by the machine tests , menu #4, processor tests #2 main door and bill validator door remain at a 1)

Has anyone attempted to check into these type failures at a board level repair?   Does anyone have a decent set of schematics  that are  large and easy to read? ( my eyes are going south and I have to use magnifiers for the one that are in the downloads)

I have noticed that more of the 504 boards have this problem. anyone else observe the same?

On two boards in particular, they worked initially, had a lot of corrosion around the green battery, removed the battery, cleaned the board around the battery (corrosion green crud) , then the board wouldn't work. got one of the above messages.

Any input would be appreciated.

Jim

Tilt, you are right about the jumper being used on these boards, the second hole is there for mounting purposes only , it has no electrical connection to anything.

[Tilt]

Jim,

I've repaired a few of them.  My experience has been that most of the time if you have Door Open errors it's due to corrosion from the battery.  On a couple of them that didn't have corrosion problems but had door open errors U92 was culprit.  I've repaired a couple that have had minor corrosion issues by using 30ga wire to replace the damaged trace. 

Most of the problems I've seen are on 502 boards.  I suspect that that may because they're older (so the batteries are have been corroding longer) and more of them out there. 

Take some photos of your test setup when you get it done.  I was going to make a test bed, but never got around to it.  I used a test lead with microclips ran through the hole in the tray to look at signals with my oscilloscope.  It was a real pain, especially powering up and down everytime I needed to more the lead to a different component.  Something to do while you drink beer I suppose.

The only schematics I have the MPU board is in the S2000-I Field Service Supplement.  I can email to you if you'd like.  It's ~3.5MB