Hello Everyone,
I've been subbed to John's YouTube channel for a while now, and finally through searchtempest I was able to pick up an original for $400. I had seen John's video on how to fix a Dead video game and took a little bit of knowledge with me into the negotiation. He wanted $1,000 for the game and when I arrived I noticed the picture was dark, very dark indeed could only really see the ladders and girders. The seller told me he tried ti turn up the brightness but that was as far up as it went. He asked me if I knew anything more about the other pots in the back and I said abd he agreed the game  may have a monitor issue. I figured I would let him diagnose the problem and perhaps save some money through his own admission. He also pointed out some other flaws on the cabinet and in the joystick as well as no coin locks or keys. So after I inspected the machine I asked him what he thought a fair price would be. He told me that since it seems like he had a monitor and joystick issue if $500 would be okay, I asked him if he would take 400 cash. He immediately agreed and I brought the game home. So im not sure I got a great but.. ut eas a bettwr game thab I expected and I paid less than I thought.
When I got a cabinet in my basement I turned up the brightness on the monitor all the way to no avail. The picture was still quite dark so I found on the schematic the RGB pots and brought them up and the picture looks beautiful. Needless to say I was very very happy. And other than some very fast vibrating of the picture occasionally I think so far this is a very sound game. I'm having some issues with the joystick. I've taken the control panel off and clean all the joystick components after I took it apart. I never knew there was a blind plate in the panel but as I was reassembling it I noticed it was cracked and broken with a sizable notch out of it. I put the joystick back together and the control panel back on the game and noticed that it hangs up in the middle when I try to move Mario especially from side to side. The joystick moves a lot more freely and is now centered but the hang up issue is still there.

My question is does anyone think the blind plate could be causing this issue because it is cracked and broken, or should I just buy replacement parts for the joystick?

 Also beyond that issue I was wondering if anyone would take a crack at telling me first steps to bulletproof this machine ( capping monitor adding a switching power supply adding a high score kit Etc.)  I have done rudimentary soldering but I am very new to this and would enjoy taking my time and learning something and playing a game I've wanted for 40 years!

Please give me your thoughts! Thanks!