I bought an NVRAM chip for pinbot a while ago and just got around to putting it in. I removed the batteries from the battery pack (but didnt unsolder or remove the pack itself yet). Then, I unsoldered the U25 chip and soldered in the socket. I then plugged in the NVRAM chip and put the board back in Pinbot. When I turn Pinbot on now, the lights turn on, but the cpu is locked up (game doesn't boot, nothing on the displays, etc.). I checked that the board is getting the correct voltage (and it is). I also checked and made sure that the chip was getting continuity to the correct locations on the board at each pin. The game was working perfectly before I installed the chip, so not sure what went wrong. Anyone have any thoughts?

Appreciate your help.

Thanks,
Bill

Thank you both for your replies!

The chip is oriented correctly.

I checked to make sure there were no solder bridges created, and checked for continuity at each leg of the chip so I know that none of the traces were damaged.

Unfortunately, I cut each leg of the chip to make the unsoldering easier (made it easier to not damage any traces pulling the whole chip out) so I can't just plug it into the socket. I guess I might have to buy a replacement U25 then just to make sure it's not the NVRAM itself.

Here's a picture of the NVRAM. Not sure what you mean by what processor I have - all of the boards in the machine are original.

Ordering the old memory chip might be the next step.

Also, I was checking continuity between each pin to make sure that I don't have a solder bridge (even though visually it seems clear that there are none.

I am getting continuity between pins 6, 7, and 8, 17 and also between 9 and 10. It really doesn't look like there are any bridges though. Anyone know if this is normal? Otherwise I might have to unsolder the socket completely and then check for continuity between these pins with the socket out. Then resolder the socket back in. I am reluctant to do this because the solder joints look good though.

IMG_9340 (resized).JPG

Hm, I actually saw this article, but I used the 6116 NVRAM, and pinbot is a system 11a so sounds like I should not have to worry about the jumper.

Here's a picture of the top and bottom of U 25. Think it's worth removing the socket and resoldering?

IMG_9341 (resized).JPG

IMG_9345 (resized).JPG

Thanks - bet this is the issue. I'll do that now and report back.

Yup - I believe this is what happened. Desoldered and cleaned it up, and after resoldering the socket and plugging the nvram in - it now boots up! Thanks for your help.

Although - now when I press the start button instead of starting a game up it just displays the rules for Pinbot. Hoping that it shouldn't be too hard to figure out though. Might just be a setting or something... I'll have to report back.

Yup - just came here to post that you just need to set it to free play. Everything is working great. Thank you all for your help!