Neo Geo CD Neo-Geo CD problem. Random restarts.

Hello.
I have a problem with my PAL neo-geo cd system. It worked perfectly until some time ago, then started just restarting at random occasions (like power went down, then suddenly back again)
Now it restarts quite for some times in a row and there seems to be no pattern to it.

I only noticed that when you leave it alone for quite a while - it gradually begins restarting more rarely.

What could be the problem? Is it the impulse block or something else?
Don't tell me to fix it elsewhere. Nobody services them anymore anyway.

Unlike a computer there's not much of way to test the components beyond using a muti-meter. Even a computer it isn't always cut and dry. The other problem is that most everything is on the main board. I suggest you get a new one. Trying to fix this one is going to cost you more in the end.

I'm good with electrical equipment so it will not be a problem to repair. Just want to know where to look actually.