The board can take a 6116 or a 6264. If you put in a 6264, a jumper will be required to be moved. Can you post a picture of your board please?

I don't see this being necessary at all. With it, can come more headaches.

That needs to be taking care of first before doing any work to the board

I was also wanting to see the area above and below the battery pack area. Fumes can do more damage and go undetected.

Is the 5volt LED lit when you turn on the game? You did mention the other 2 were off.

May need a second set of eyes. First take a picture of the entire board while it's connected in the game and post it here.. leave the resolution large enough that it can be zoomed in on some. Might be something to spot there.

If not, you'll have to pull the board and take a picture of the front and back side without the NVRAM or chip installed at U25. Sometimes it's difficult seeing if a thin trace connecting to a pad was affected. Won't be able to see under the socket much, but maybe something can be spotted there.

Also, do you have a meter just to check if the game is getting proper 5v/12v at the test points?

You may also have to pull the schematic and manually verify continuity between the U25 solder pads and what they're connecting to on the schematic. And also verify no shorts between adjacent solder pads/pins at that U25 footprint.

I wouldn't think you need a new MPU just yet. Something went awry with the install it would seem. Or it exposed another issue that was present. Hopefully some pictures and/or using the meter to check some things can shed some light on things.

This in itself sounds related to the work performed. Do you have a logic probe? It definitely helps find problems easier/faster sometimes.

Already checked for shorts as mentioned above?

The Rollergames schematic online looks pretty good on page 91. Make sure you check for continuity from the top of the game ROM pins to the top NVRAM pins on the top side of the board as this will aid in testing the traces that are directly under the NVRAM, which is more likely where a trace was separated from the pad, if that is the case.

https://www.ipdb.org/files/2006/Williams_1990_Rollergames_Manual.pdf

httpswww.ipdb.orgfiles2006Williams_1990_Rollergames_Manual (resized).png