I have a Silverball Mania (1979 Bally) and it has an AnyPin NVRAM chip in it. It has a problem holding the game adjustment settings though. It'll be fine for a bit, then things will become scrambled, like the high score, credits, book keeping, will just change at random.

I checked the socket that was soldered in for the AnyPin, and touched up the solder to make sure it was connecting on both sides of the board. The board has had some minor battery damage near the edge (I think) because the outside ground strip has solder along the edge, but it looks like it was done by someone that knew a thing or two about it. Nothing else shows any sign of damage, the chips/sockets and components are clean and healthy looking. I've removed and reseated all the socketed chips, and reflowed all the solder on the connector pins.

Could the AnyPin nvram be faulty? Doesn't seem that likely that it would be, but any input is greatly appreciated, thanks.

Thanks. I tried putting in a 5101 off an old board, and hooking up a battery pack but the mpu wouldn't boot. I don't know if the 5101 was dead or if the mpu had other problems. Putting the any pin back in and removing batteries brought it back.

IMG_0497 (resized).JPG

IMG_0498 (resized).JPG

IMG_0499 (resized).JPG

The backside of the reset section.

IMG_0500 (resized).JPG

IMG_0501 (resized).JPG

I went over the mpu again and gave it a really good cleaning, then inspected it with my dmm and magnifying glass. It doesn't seem like anything is shorting out that I can tell.
It's running now, and if it's going to screw up again it will happen at some point today. I'm just going to cycle it with some time on, then time off.
I'll let you know if the extra cleaning helped. Thanks again for your input.

That didn't take long, it screwed up already and seems to be getting worse with time.

When you say ram can go bad, are you thinking the anyPin nvram?

$325 cdn shipped for a new Alltek board that would cure this, butI'd rather not go there if there is a way to keep it original.

Thanks again for your input.

Thanks, and sorry but you lost me on the last part. Also my dmm battery just died so I'm unable to check voltages till later. I don't have a listing for what voltage should be at tp6, is that the voltage I should check? It's the tp beside the nvram.

I should mention one thing I did at the recommendation of someone who did this and it worked for me. I was having issues getting the mpu to boot consistently and he said putting a 4.7uf cap across R2 would help give the reset section more time on startup, or something like that. But it cured my startup issues and it has fired up every single time since.
Do you think this could cause the scrambled memory issue?

Seems like it's holding my game settings for rewarding replays, but the high score resets to 48000 and credits can change. It doesn't do it every time I restart the machine, but like I said it's getting worse.

Thanks ace, good points and leading me more towards a new mpu and keeping this old one for parts. I'll tinker a bit more and look at the pads you mentioned.

Thinking about the extra capacitor, and was wondering if it's holding a charge longer than I thought. I always let the game sit for at least 20 seconds before turning it back on.
So far, if I let it sit a few minutes between startups it seems to keep the high score etc. Just a theory, and will test it out throughout the day.

It's not locking up since I added that capacitor to R2 Quench, but if I take it off it would boot once in a while, unreliably.

Thanks for the great info! So, just jumpers in place of CR5 and CR7, and totally remove R11? I wonder if that will help it boot reliably without the cap in there?

I've been testing it and 30 minutes with the power off seems to be what it takes to restart the game and not mess up the settings. I will try to do the fixes you've mentioned, but might need a little clarification. I love the hobby, but still have much to learn. Thanks again.

Thanks, I'll be doing that mod, and I understand it probably won't solve the issues I'm having.
I took out the mpu again and went over the solder once more on the nvram socket. It seemed like it helped but alas settings were lost again. I tried removing the capacitor on R2, and it still lost memory, and only booted up every 5th time or so. I put cap back on and it boots perfectly again.

AS2962-13, mpu 1157
My Voltages are:
TP1 4.95
TP2. 12.7
TP3. 21.5
TP5. 4.95
TP6. 10.6

Ok thanks. I tested it with logic probe at power on, pin 40 of U9 is flashing high and staying there.

It still boots up fine though, and for the record the cap is still on r2.

Edit: I just found another 6800 to try in there and it's the same pulsing high from start.
And just found another 6800 that I know is good, same thing.

New Alltek mpu ordered, this old one is going on the shelf.
I appreciate all the input, thanks very much, but it's going to be good to have a nice reliable board in there. The rest of it's in pretty good shape, so it's worth it.
Thanks again.