problems with G07 CBO monitor in Moon Patrol :(

[vintagegamer]

Hello all,

I'm trying to nail down a remaining glitch in a G07 CBO I have in my Moon Patrol.  After about 15 min of power up, the screen gets the jitters, almost like if you messed with the H Freq pot.  It lasts for about 30 secs and then goes away.  Prob is, it happens while you're playing a game and it messes up the graphics so bad you can't see well enough to keep playing through it, so you end up dying.

I did a cap kit from Bob Roberts and although the screen looks much better, this jitter still continues.  There are 3 caps I did not install, because the originals are under a metal plate down at the front of the chassis (when it's installed in the machine) and I didn't know how to get that thing off.  I used all of the rest of the caps in the kit, including the one that needed to on the neck board.

I have reflowed the solder on the 2 sync header connectors in the upper left corner (the 3-pin and 6-pin), and I also reflowed the solder on the header going to the yoke.

Again, it's a super minor glitch, but it's just enough to piss you off when you're playing!  I only have one other game that I think has a G07 in it, and it's my Robotron.  I'm nervous to pull the G07 from that though to put in my MP because obviously I don't want my Robotron to start having issues as a result.

If anyone can provide any suggestions I would greatly appreciate it.  I almost wonder if it's a bad ground because the ground straps are cut in different places in the cab.  If someone could tell me how to appropriately ground the chassis and/or tube, I will happily give it a try and see if that fixes the issue.

Thanks in advance,

VG

[vintagegamer]

Forgot to mention I have a B+ voltage of 119.2v