Not doing anything at all? Check wiring, cold solder joints etc etc. Check continuity on coil. Also check fuses on the board most likely a blown 40v fuse somewhere or whatever.

Try those basic things and report back.

Flippers are enabled by the Q relais. Try to check this by pressing it manualy.

If the Q relais is'nt activating check your scematics to see witch transistor drives the relay. But dont forget that the CPU - Driver cable is real troublesome. I (and this is not the nice looking way to do) always solder the wires to the boards.

One of the important thing if you buy a system 1 flipper is to see if the displays are working... (if thay work the game probably boots up).

Gottlieb is just my cup of thea

After reading up on the system 1's, they seem like a real PITA compared to a Bally/Sterns.
Question: Did the seller seem like he knew anything about pinball machines? Often, they will say the flippers don't work, but they may not have even removed the glass to check the rest of the solenoids. They just don't know any better. On these early Gottleib games, it might be something as simple as the coin door slam or roll tilt switches being "open", which will cause the game to not boot up. Try and close the switch and see if the game boots up. Especially if they are really corroded.

Funny stories kinda on similar topic.
My roommate's girlfriend called him up crying because her car wouldn't start and she didn't know what to do. So we drove the 45 minutes to the mall and after about 15 minutes of tinkering around, found out she left the car in Drive when she shut off the engine. We put the car in Park and it started right up.
My Grandmother couldn't get her steering wheel in her car to move so she called me and I drove to her house. Car started right up. Steering wheel turned no problem. My guess is she didn't push in the brake pedal so the steering wheel was locked. We took her keys away later that week to save lives.
Moral of the stories, "some people aren't very bright." But most people just don't have the knowhow or inclination to troubleshoot. Hopefully you get a hidden jem because the old owner panicked when "it wouldn't work right."

Yes good point SC,
I helped a guy once and he didn't even know how to raise the playfield and set it against the backbox .I watched in horror as he bent a few relay return springs on an old GTB. while I was looking for the problem.
- just remember the sword cuts both ways,
if you come across a pin that 1/2 works and the guy selling it is also good at fixing pins
you might want to think twice about such a bargain price
Ask the seller if he works on them, if yes proceed cautiously.

True, Autumn.
The old owner of my Future Spa said he was trying to figure out why it didn't work but didn't even know you could remove the playfield glass. I'm not sure how much troubleshooting he did.

Lot's of good points. I'm waiting to see if I get a Torch pinball which is also a Gottlieb system 1. The guy selling it didn't know you could fold the backglass portion down. I doubt he knows how to remove the playfield glass either. He's had it fixed a few times by the local company but knows nothing about doing it himself. It's broke again and he's sick of it. I've never owned a GS1 but others have mentioned what a PIA they can be.

Well i repaired a lot of Gottliebs and once you got them bulletproof (goundmod) and did all mandatory fixes thay are more relible than Bally or Williams pinballs.

Well I'm Glad to hear that Benboogaard,
all I ever read/hear is how bad they are and never read about the positive side

http://www.pbresource.com/boards.html
For all you Bally, Gtb solid state fans just an idea what might be needed to get a dead game up and running. Figure the price of the game and/or worse case scenario (+$ boards)
might help with any decision for a winter project - good luck

For the price alfadogmusic don't write it off. Alot of time it's a simple fix. Have you ever been to Vegas ?? .. if so you know what we mean. We'll also be here to help with fixing it and I will soon have the same system to dig into and help you back. It also seems like Benboo... has some experience with these too who can help.

Here's my opinion. If the Backglass is near perfect, the playfield in really good shape and the cabinet in good shape, then I would buy it. Even if the stock circuit board is non-repairable, you can buy a new modern board for $150-200 and the thing will run with minimal if any trouble. New bulbs, ball and rubber will cost you about another $35. So for just over $400 you will have a nice looking pin. But ONLY if the rest of it is in very good condition. Otherwise, I would pass.

That's true Brokedad could be something really simple