Gottlieb Teed Off CPU Problem

[adhl]

Hello everyone,

First of all, for clarification, I’m using a translator, and I apologize if that sometimes makes it difficult to read.

The revision of this system 3 was almost complete, some problems of flash lamps and suddenly, without any apparent reason, led fixed or off on the cards of the pediment...

- no beep at start-up
- more display on screen (DOT)
- Fixed led on CPU (A1), Auxiliary Sound Board (A20) and Display Control Board (A8)
- led off on sound board (A6)

+5V OK (now).


Voltage on connector A4J1 of the display:
- pin 1: -113 V
- pin 2: -101 V
- pin 3: 0
- pin 4: 0
- pin 5: 0
- pin 6: +5V
- pin 7: +12.9V
- pin 8: +66.7V

The sound board led being off, I also wanted to check its power supply:

- C18: +5.4V
- C10: +12.7V
- C19: -12.2V

Leaving only the CPU connected: the led is then off.

I note however that by reconnecting P1 or P2, on the CPU, the led remains lit fixed....

CPU crashed? Down?

For accuracy, by checking the +5V, it had gone over 6V.
Immediately readjusted to 5.2 but still no change.

And 500ohm adjustable resistor replaced to prevent the problem from recurring.

Which component could have been impacted on the CPU and would have to be replaced? Other boards may have also been damaged?

This is apparently a known power issue on systems 3, can you help me identify damaged components and boards?

Thank you in advance!

[adhl]

hi

No ideas or advice?
No one has encountered this problem?

It seems known but I can not find which components must be replaced when the +5V goes to +6V...

[Mr. Dinoman]

Try this link:  maybe it can help you...Lots of information on system 3..
http://www.pinrepair.com/sys3/

[adhl]

Very interesting indeed but a little technical when you do not master perfectly English.

So I found this:



5 Volt Problems (too low or too high).
The biggest problem with Gottlieb system3 power supplies is the 500 ohm trim pot at R3 on the 5 volt power supply. This trim pot is junk, and often shorts or goes open, causing 5 volt problems. It can short sending way more than 5.2 volts down the 5 volt buss, stressing all the logic chips. Or it cannot allow even the minimum of 4.9 volts needed to run the system. I have seen System3 games that worked fine for five minutes, then reset. This was caused by a bad R3 power supply pot which allowed the +5 volts to vary. My suggestion is to REPLACE this trim pot with a new high quality 500 ohm version.


Should logic chips be replaced?
If so, can you help me identify them?

[Mr. Dinoman]

Because just about every Ic uses 5v you might want to consider just getting a replacement MPU/Driver board...Much more dependable as the way gottlieb connects the driver board to the MPU board is terrible and unreliable...Little expensive, but might be worth it instead of trying to replace Ic's and still might have other issues...

[adhl]

Thank you for returning.
The cards are still repairable unless I am mistaken?

It’s not disposable, though?

Some of these integrated circuits are perhaps less fragile and could have supported a 6V switch.

Which ones, on the other hand, can absolutely not withstand a switch to 6 V?

[Mr. Dinoman]

If you want it repaired, I would recommend this guy....

https://chrishiblerpinball.com

[adhl]

I wanted to repair it myself to limit the cost but to do this, I would have to be able to identify the integrated circuits to replace...

[Mr. Dinoman]

I have a manual with full schematics of a system 3 game if you need it...
Let me know...I will need your email address to send it to if you do...

[adhl]

I have the manual of this game, I do not know if that is what you were thinking or if it is something else?

Unfortunately, I have a lot of trouble reading these different patterns.