Definitely worth saving, this is a fun game to play. First if you haven't already, download all the documentation from ipdb. Do you get the 6 red led flash when powering up? Take your time and you will learn a lot along the way. It's sounds like you have multiple issues so focus on one at a time. Mine was DOA and I have replaced components on every board. Definitely check out the area Force Flow highlighted. There is a lot of good information and knowledgeable people on Pinside to help you out.

Mark, is that sound one of the the sound the machine uses? I must confess I'm more familiar with the SSU-2. Sounds like something is latching on. I you can narrow that down and follow it back though testing components along the way. I'll take a better look at the schematic later.

Do you have the battery hooked up? (external, remove original)

Glad to see it working. Can't help you with the c and o. Is it controlled lighting? Excuse my ignorance.

It looks like it uses a PSU-1 power supply. I don't see a schematic listed under Andromeda on ipdb but there is one under the Sharpshooter schematics you can use that to help troubleshoot the power supply.

When I tested my PSU-1 I had it out of the machine and hooked up with a temporary cord to plug it in. I checked voltages to the case (ground). I can't speak on the MM though.

I may need a picture to understand. It is a SDU-1 board, correct?

Ok, if my memory serves me correctly (might be a big "if"), they don't have any as they drive the relay(s). Most only have one relay for the flipper circuit but I believe Andromeda used a second one for a spinning target or something like that.

That's it!

Ok, I think Super Nova used both relays as well. The schematic listed for it is the same one as the Sharpshooter. Not sure if that helps any. Are you having issues with the SDU board?

Batteries installed?????

Man oh man. The battery took it's toll on this one. I guess it all depends on how much time you want to put into it. Replacements are hard to find so repair is a little more lucrative. Echo Lake makes MPU runs occasionally and sells them for around $300 IIRC. You could start I guess and see what damage is done. Cut the battery, neutralize the acid and check traces then move on to the components.

It looks like Marco's has the ROM's, not sure of the quality though.

check Q39

Let my try to remember back. You may want to check U2, U3, U4 on the driver board. I think I had 2 of these that were bad. I found some replacements from China but they were junk and all the solenoids would lock on, the same as if there were no chips installed. I put sockets in when I replaced the chips and tried it without the chips. I then bought a set of used-refurbished ( I think from Ed but I can't confirm) ones and they worked fine and solved that problem.

Check with Ed at Great Plains, I think he sold me used ones. If not maybe he can steer you in the right direction, great guy.

Yes, Vinegar. I moved the batteries to the side of the backbox, added a blocking diode and just use Duracells.

Do you get 6 flashes on the LED when powering on?

Do you get any flashes on the MPU led? Maybe check the 5v a the mpu with the displays hooked up? Viperrwk (OP) was a great help with Game Plan trouble shooting but he has been MIA for over 2 years now.

He was such a great asset. Not sure what happened to him. Hasn't been around since 2015.