Break could be on the ground side. Remove J205, power up and carefully use a jumper between J205 pins 9 and 10 (ground). If it works, goes into diags, break is likely in ground wire downstream of CPU board or coin door board issue (unlikely). If it doesn't work, likely CPU board issue.

Couple things. A wire could have broken off a solder tab of one of the buttons on the coin door. Also, opening and closing the coin door for 30 years can break a wire inside the wire bundle. All the coin door functions pass through the coin door board inside the cabinet on the left side. Try reseating the large connector on the left and right side of the board. If I remember right, the coin door buttons are not part of the switch matrix.

Post a pic your cpu...

Coin mech switch off/broken?

You have extensive light and localized heavier alkaline corrosion. It's the green/blue crud.

wpc-89_cpu.jpg

This will interfere with switch state detection logic.

That CPU doesn't look minty fresh, although it may taste that way.

Every time 'wpc switches aren't working' gets posted, its corrosion I swear. Even if a remote battery holder was installed doesn't mean the previous batteries did not leak. The only thing mint about the cpu, is the mint green corrosion

Yes. I have a reproduction board that works in a T2. It is WPC-89 (standard).

If you want a fancy one, you can place a bid on the purple one at the Project Pinball auction @ https://projectpinball.rallyup.com/pinballexpo-2022-projectpinball-silentauction/Campaign/Details. Current bid (as of post writing) is $95.

Otherwise, please contact via PM for more details.

Sometimes it's not corrosion and they crossed some wires under the playfield instead, blowing out U20. U20 is for switch matrix, this problem was a dedicated switch. Always keep a spare U20 in your toolbox if you work on WPC games regularly. Note that U20 is socketed on this board. And if that fixes the game, tell the owner to stop crossing wires (or disable high power) when they're changing light bulbs.

Your friend will need to neutralize the alkaline before it causes any severe damage but I'm sure he knows that. You probably just have some bad connections on those chips at the moment.

I had a similar issue with a newly acquired T2 where it would randomly reset even though it had 5.02v on the CPU board, new connectors, 5v section rebuilt, pins cleaned, everything in pinwiki WPC 5v reset troubleshooting followed, etc. Turns out it was corrosion at the ASIC chip/socket causing the reset. I too had light corrosion on the lower half of the board, like yours. I had a few odd switch issues too.

I pulled the board and pulled all the chips including the ASIC chip. Don't try to pull that chip without a real ASIC chip puller - but you can get one cheap on Amazon. Then the entire board was cleaned and alkaline neutralized with vinegar and a brush. Then all were rinsed with water, blown out, and then cleaned with an alcohol flush to displace any remaining water. Set it all aside for a few days to completely dry. New ribbon cables were also bought and all reassembled.

It's been rock solid since. Good luck. Let us know how it goes.