These kind of machines are my favorite kind. Good luck on the restoration. After cleaning corrosion I would change the 40 pin interconnect between the two boards.

Just go slow, gentle, and careful with that cleaning on the playfield. Looks really dirty but all the major wear spots also look to be really good from the photo. May have a real diamond in the rough there.

-Hans

Wow, pretty filthy! Should clean up nice though.

These checklists should help:

https://pinside.com/pinball/forum/topic/post-purchase-checklist
https://pinside.com/pinball/forum/topic/shop-job-master-checklist
https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6

This board should help protect your MPU in case any coils lock on:
http://nvram.weebly.com/repair--conversion-kits.html

This is a great idea for all machines. Can you buy one for system 11s or WPC ?

The very first thing I do is turn the bottom cabinet upside down and glue all the split/loose plys of wood. Also glue any particle board that's crumbling. At least get the cabinet to a point it can be moved without shedding parts of itself on the trip.

Then scrub the cabinet around where the legs mount (unless it's a cabinet repaint, I'd do that next).

Then wire brush/sand/paint silver or replace the leg levelers. Whatever level of reconditioning you're shooting for.

Then the legs. Same as above, depending on what level you're after. When the leg's inside is really badly rusted I sand them down smooth and spray them black. The outer surfaced is either polished/painted/whatever provides a cosmetically attractive surface.

THEN install the legs on the cabinet and actually start vacuuming with a stiff paint brush.

You're still WEEKS away from plugging in the power cord that you replaced with an extension cord or at least replaced the plug with the broken off ground prong.

I'm on the lower end of "hobby level" Rattle-Can Rejuvenations(TM):

https://pinside.com/pinball/forum/topic/the-long-road-to-the-world-cup-or-how-i-ruined-another-one
https://pinside.com/pinball/forum/topic/started-on-the-next-reconditioninga-gottlieb-baseball-from-1970
https://pinside.com/pinball/forum/topic/8-ball-deluxe-playfield-reconditioning

That's pretty messed up right there but.... mine was almost like that and it's AWESOME now. Take your time and let your wife know it's a great machine. AND it was probably cheap, even better.

IMG_0659 (resized).JPG

If you are talking about the last picture the overheated looking things are the strobe lamp resistors. They run hot. You can replace them with 5 watt resistors (Williams used 3 watt) and reduce the heat or you can replace the associated transistors with mosfets and use a 1/4 watt resistor and eliminate all the heat. The mosfets are probably like $4 each.

Yes that's the area. They build a LOT of heat. If things are working they are ok but for the cost and the heat reduction you can change them over if you can solder pretty easy.

The 40 pin connector looks original and that needs to be changed so you won't be chasing ghosts when things start locking up or going wonky.

Pm me an address and I will stick one of these in an envelope for you. It goes under the top kickout plastic to keep the ball from hitting and breaking your plastic. As they get older they are more likely to break.

IMG_2374 (resized).JPG

Make sure that you have zero ohm /jumps on
the switch matrix. That board is an older
board for the early/late 1970's games.