Hey Nepton,
I have a 4slot and a 2 slot MVS cabinet that I had to do my fare share of cleaning and fixing to get working and looking decently. First thing first. These cabs are are from 10-15yrs + old so if anything goes wrong I would advise not to hit or bang on the cabinet. Your probably making things worst. Your first post said you were playing the game and it went out on you. Was it just the picture or the entire monitor and the cabinet.
Guess #1
If the monitor went black and the game stopped working chances are that the main MVS harness that plugs into your 6slot motherboard is loose. If it is, it will kill all the power and shut the system down. So check that first. If you don't know what it is, its the long flat connector that is the largest plug that goes into your board. Also check to see that the wires that are going into the harness are not loose and popping out. There's a nice little sync wire that if it gets loose will cause your monitor to flicker.
Guess #2 I would not advise looking at these options until you get your friend or do more research. The monitor is very dangerous and you can kill yourself due to high voltage risks if you are not careful. The RED ANODE CABLE that goes to the back of the monitor tube is very dangerous
If the monitor went out or started to flicker and you can still hear the game working it can be many things. Here's a couple of easy guesses.
1. The harness or wires that connect the Neo Geo motherboard to your monitor is loose or going bad. Its typically known as your RGB connection. This harness gets loose sometimes threw moving the cabinets. Worse case, your solder points for the connecton pins on your chassis is bad.
2. Power cable or harness that goes from your power supply or isolation transformer is loose. Or even worse the isolation transformer or power supply it self is bad.
3. Some of the newer monitors have a small board that will usually have a controls knobs(or pots) for contrast, brightness, v-pos, h-pos, etc. This board is called a remote board because it has long wire attached to the monitor chassis so you make adjustments while looking at the monitor itself. The remote board cab be detached from the wire harness at its end and also on the monitor chassis end. If not attached properly the monitor will not give any kind of picture or flicker.
Problem number two
You are blowing fuses. Your power supply can be going bad. You could also have a bad ground or misc wire rubbing/touching. Last but not least, six slot boards from what I've heard are the least reliable of the multi slot boards. So maybe your board its on it's way out.
Too many things to look into, but I'd try these basic things with help first before you do any monitor chassis recapping or replacing!
