Gottlieb U8 chips?

[deathrow]

Trying to find a source for a programmed U8 chip for a system 3 NOES machine.

I might be barking up the wrong tree though so please read.

Bought a NOES machine that has two solid led's only. One on the CPU and one on the DMD driver.
Searching shows two conflicting views... One said that the system 3 main board will boot with just 5 volts etc and another source said you cannot boot a system 3 cpu without the dmd board connected?

I can see evidence of someone playing in this machine with connectors and I know that unplugging the dmd while the game is on will fry the U8.

I do not have garbage on the dmd... I have nothing at all.

Backbox lights up and the GI on the PF is lit. Thats all she wrote...

Done the usual 5 volts issue with the cap and have a lovely steady 5.03v. This may have gone higher before though.


Maybe I need a whole new dmd driver as this shows signs of many tampering sessions...

Help? cheers

 

[Poibug]

I know U11,a 74hc123 can cause problems at boot up.
Someone once had an intermittant boot problem where dmd would be blank(like you),and a new U11 fixed that

with everything else disconnected other than power does it boot differently - ie led's change?


poi

 

[Poibug]

A1 CPU Control Board LED.
The CPU board's single LED will flash continually and evenly if the board boots correctly. If the CPU board's LED flashes very fast for a second, then pauses just a moment, then repeats, this usually indicates a low CPU board battery or a bad U11 chip.

A8 Dot Matrix Controller Board LED.
The DMD (Dot Matrix Display) Controller board's LED should also flash continually and evenly (but not quite as fast as the CPU board's LED). If the DMD Controller board's LED is stuck on, this usually means there is a problem with the custom GAL (Generic Array Logic) chip at U8. The GAL is a programmable chip that replaces several 7400 series TTL logic chips. A bad U8 GAL chip will also cause the DMD to show "garbage". This chip is available from a number of sources (but must be programmed).

 

[deathrow]

I know U11,a 74hc123 can cause problems at boot up.
Someone once had an intermittant boot problem where dmd would be blank(like you),and a new U11 fixed that

with everything else disconnected other than power does it boot differently - ie led's change?


poi

Thanks

with all disconnected i have a solid red.

 

[deathrow]

Should the main board boot without the dmd board linked to it?

 

[deathrow]

well that has people stumped lol

Any idea where I can get rebuild kits for a system 3 in the UK?

Thanks

 

[Moonraker]

Should the main board boot without the dmd board linked to it?

I think they do.

It sounds like it could be a fuse problem if you have no display. There is one next to the transformer under the playfield that can cause a no display problem (can't say which as I have no machine near me at the moment). It may not be the fuse itself but the fuse holder so I would check there first...

 

[deathrow]

Thanks,

Unfortunately I have been there and checked all of the usual issues.

One of my other gotts that I used to have would not boot or display unless all boars were working. This included the sound board?? so many conflicting views on these system 3 boards online.

My external power supply isnt working correctly so I feel thats the reason for the two sound boards not working.

The opto board under the PF is down too.

Going to rebuild all of the boards if I can get the kits and go from there....