The issue I am having with my pinbot is a wierd one.
After the machine is on for about an hour I loose the pinbot speech.
All other sounds work fine.
A quick off/on with the power switch and the speech is back.
Another hour passes its gone again.

It comes back every time I switch the machine off then back on.

So far I replaced all the caps on the sound board which has the speech rom on it.
Reflowed all solider. Checked all wires etc going to it.
Also replaced the 69BO9 processor.
And both TDA 2002 transistors. And new heat paste.

Im completely stumped.
Any Ideas?

I figured i would unplug the power jumper going from the mpu to the sound board.
And hit start. This simulates the issues as all othrr sounds are working except speech.

Plug it back in and speech works fine. Now i just have to figure out why its loosing power to the sound board after a hour or so.

Anyone have any ideas?

Replaced the caps on the mpu today.
Problem solved.

So if your pinbot looses speech its not specifically the sound board with the speech rom that is the issue.

So I thought the issue was fixed. Turns out it takes about 3 hours now. But it still has the same issue.

This is driving me crazy!

All connectors are new. All pins reflowed. No cold solider joints on any connector pins or anywhere else on the boards.
Could it be a bridge issue that is going open.

If I unplug the power going to the soundboard. It simulates the issue I am having where all other sounds work except sppech.

Just seems wierd that as I replace components the time it takes to act up has gotten longer.

But still as soon as I turn the machine off and on the problem goes away for another 2+ hours.

It was about every 1/2 hr.

Bump, just incase anyone has any insight.

I am wondering if I have a U23 ram error.

Does anyone know what the tone/tones should be on a working pinbot with the cpu sw1 sound test button.
I get what sounds like a scratch and explosion. I cant tell if its one tone or two.

If its two, its working correctly.
If its one I have a ram U23 error.

Just want to know before replacing it.

Any help would be great.

Also how warm does the yamaha ym2151 get on your sound board.
Mine seems a little hot. Going to replace that too.

After I find out what a working test tone should sound like.

The problem is fixed. If anyone has this issue it is the cvsd chip on the mpu.

The chip fails evetually under load. Once th machine is rebooted it works for a bit then eventually fails.

Replacing the chip has resolved the issue.

Woo hoo!!

The chip needs to be desoldered. I put in a socket for the new chip so I can swap it out if it ever goes bad again.

If you lose sounds. And turn your machine off and back on and they come back. Then eventually drop off again It is 100% the cvsd chip at U3 on the mpu.

No its just an off the shelf part. Marco has them. But for cheap. Probably eBay will be your best bet. Unless you post a wanted ad on pinside. Someone might have extras.
http://www.marcospecialties.com/pinball-parts/5370-09691-00