For replacement power supply, you may want to try Kohout's boards:

http://pinballpcb.com/products/williams-system-7-11b-power-supply/

You'll have to determine which version you need though. Whether the main transformer is in the backbox or if it's in the cabinet should help determine which power supply you'll need to order from them.

Silly question, but is the game set to free play? If it isn't, are the coin switches working? Game won't start without credits (or set to free play).

Which switches are the balls activating in switch test? List the numbers that come up.

Do all the coils fire properly in coil test?

I was kinda thinking the same thing--if the memory got scrambled when it locked up, it might have removed the free play setting from the settings. Did the game ever boot to audit mode recently? When the game boots to audit mode, only the general illumination lights come on and some numbers appear on the displays. When that happens, you have to open the door and flip the power on/off/on to get to attract mode. If it did that, it's very possible the free play setting got erased/reset.

Post pics of both left flipper assemblies under the playfield. Maybe there's something funky with the wiring or a possible intermittent short someone might be able to spot from some pics...

Sounds like he's looking for pics of the mpu (top left), driver board (bottom left board, connected to mpu via big 40 pin connector), and power supply board (top right)