Found the following on Pinside:
BEFORE you turn it on review the following:
- Batteries: replace batteries and ensure battery holder has no cracks or broken contact points. Examine below the batteries and ensure there’s no damage. (Eventually, get the batteries off the board completely)
- Boards: ensure all the boards in the backbox are mounted and grounded with screws. Several reasons for this. (Frequently there are some missing, which can allow for more board flex when plugging connectors back in. More screws = better grounding.)
- Coils: Check the resistance of each coil against the spec. Check each arm and make sure there’s no resistance to movement. Check each lug and look for broken/loose wires.
- Docs: Get your game’s documentation at http://www.ipdb.org
- Flipper Coils: check them against the specification for right type. Inspect flipper switches.
- Fuses: Check fuses against the specification
- ICs: Make sure no socketed ICs (integrated circuits — “chips”) are installed upside down
- Loose Items: After setting up the pin, before you plug it in, check the cabinet and back box for fallen loose items, using a bright light — make sure no small parts have been wedged in somewhere
- Power Cord: Check the power cord for damage and fraying. Be sure there is an undamaged grounded three prong plug installed.
- Serial Number: Record the serial number, take pictures for your records
- Voltages: Check the voltages on the rectifier board (with connectors unplugged) — see various troubleshooting guides to learn what voltages to expect
- Wires: Check under the playfield and make sure no wires are getting eaten away by moving parts (sling shot wires, and wires along the edge of the playfield that can rub against the cabinet sides) Check the coin door for clipped/cut GI wires that may be dangling free.
- Nut check: A loose or missing nut can mean undue stress going to a part that is loose on the playfield. Make sure all posts and pop assemblies are well secured. Review all nuts quickly. You will likely find a loose or missing one on your first pass.
- Add Fuses: Perform this safety mod on all your Williams pins made from 1977-1987. — add two fuses to the bridge rectifiers to prevent fire.
1. Batteries were removed before purchasing and minimal amount of corrosion on the battery terminal. I will replace it with something down the road.
2. All boards are screwed in securely, but some are missing. Will need to order some more (or find some in my shop :))
3. All coils where checked by ohming them out and moving them freely. All were good with a few exceptions of some bad soldering. A number of plungers on the lowers playfield were pretty rusty and didn’t move smoothly.
6. Fuses were all good, but most were replaced with 20 or 30A fuses. Need to get the correct ones installed.
8. Machine was cleaned out before I got it. Didn’t see any loose items in the bottom of the machine.
12. Checked wires and found one loose on the left drop targets.
To do list:
4. Find manual
5. Check flipper coil specs
7. Check ICs and sockets
9. Replace power cord
10. Serial number? I will have to look.
11. PS needs rebuilt along with headers and connectors
13. Nut check. Need to double check pop bumpers.
14. Need to add fuses