G07 CBO still has horiz jitters after new cap kit

vintagegamer

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I just installed a cap kit from BR tonight, and at first it looked like it had cured all of my problems. But after about 15-20 min of running, I started having horizontal jitters appearing again. I did not replace the HOT, is that my next step? Or should I try locating a plastic screwdriver and futzing with the current dial settings?

(this is the Moon Patrol monitor that had been sitting outside so keep that in mind when replying LOL)
 
Did it have the jitter before the cap kit?
Is your B+ steady at 120VDC?
Make sure the "H center" jumper is plugged in tightly and that the back side solder joints arent cracked or bad, reflow them to make sure they are not....what condition is the width coil in? Reflow the 4 posts on it.....
 
Did it have the jitter before the cap kit?
Is your B+ steady at 120VDC?
Make sure the "H center" jumper is plugged in tightly and that the back side solder joints arent cracked or bad, reflow them to make sure they are not....what condition is the width coil in? Reflow the 4 posts on it.....

Yeah the jitter was there prior. I don't know about the B+ but I know 135V are constantly getting to the chassis (I'm not a monitor expert, just what I've learned from here)

I'll see if I can pull the chassis out again tomorrow night and check the H Center jumper. I didn't look over the width coil, but I did reflow the solder going to the flyback. The part looks much newer than the other components so hopefully that will last for a while.

I was sure to pull out the leaves, spider nests, and "helicopter" thingys that were hanging around in the Chassis body (remember, this is my SHROOM Patrol lol)

Thanks for the tips!
 
In my experience, if a problem like that starts after 15 or 20 min, iis either a flakey pot, or a shotty solder joint.

To test the B+ place an aligator clip on the tube side of the big white resistor on the left hand side of the chassis, hook that up to the red lead of your voltmeter. Place another aligator clip on any part of the metal frame, hook that to the black lead of your voltmeter. Turn your voltmeter to dc volts, turn on your monitor, it should read a constant 120vdc.....
Let it warm up and when it starts to jitter, make sure that reading is a constant 120vdc
G07 doesn't have a pot for horizontal movment, just the h freq pot, which could also be suspect, but usually when it fails the game won't sync....which leaves those jumper post solder joints, or a shotty H width coil....
 
Measure B+ like this.....
 

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OK, I measured the B+ and it's looking like it's 113. The tab closer to the transistor is measuring 171.

I just touched the point of the positive on the 113 tab, I can go back and do the alligator clip check if you need it to be more precise.

I also reflowed the solder on the width coil as well as the H Center points. Screen still gotz the jitters. :(
 
I went back and checked it with the alligator clip and the exact reading was 113.6.

So, if I need to get it to 120, what do I need to do next? (almost afraid to ask)
 
There's a pot right by the B+ test pin, use a plastic tool or wrap a small screwdriver with tape and be real careful what you touch. Clip your leads on first so you can adjust while watching the meter.
 
There's a pot right by the B+ test pin, use a plastic tool or wrap a small screwdriver with tape and be real careful what you touch. Clip your leads on first so you can adjust while watching the meter.

Found the pot, turned it a little clockwise and I think my voltage dropped. Is counter-clockwise the way to go to up the voltage?
 
Just fiddle with it a little! I uh, don't remember. IF you don't see much movement of voltage it's also possible that pot can be bad. I have one like that, in fact, which needs replacing.
 
with the power off wipe the pot back and forth around 8-12 times thru it's full range of motion. that helps clean the contacts.

then set it to the 3:00 position that should be close to where it will need to be.

then turn the power on to the game.

turn it clock wise to increase the voltage and counter clock wise to decrese the voltage.

120vdc is your target but close is fine a volt either way is fine.

Peace
Buffett
 
with the power off wipe the pot back and forth around 8-12 times thru it's full range of motion. that helps clean the contacts.

then set it to the 3:00 position that should be close to where it will need to be.

then turn the power on to the game.

turn it clock wise to increase the voltage and counter clock wise to decrese the voltage.

120vdc is your target but close is fine a volt either way is fine.

Peace
Buffett

Thank you. I tried adjusting it prior to seeing this, for what ever reason the voltage was actually going up when I turned it counter clockwise, but I have it turned all of the way to the left and it's only going up to 116V max.

I will try doing the cleaning as you mentioned and see how it goes from there.
 
it's only 116V max.
I would just drop a new B+ pot in it, Bob sells them....it needs to be at 120 I'm still not 100% convinced that is the issue though....I would pick up pot kit while you are at it and replace them all......
 
Naaaa I don't think so, HOTs are either fail or not....its obviously still working. I still stand by my original thought that its either a failing pot or a bad solder joint.....if it were mine, I would pot kit it, including a new B+ pot and get that B+ to 120, reflow the joints in the H deflection portion of the board.
Maybe one of the monitor Guru's will speak up with another idea...Mod, Ken?? :)
 
Try tweaking and tapping on the "H sync" pot, what does it do?
I'm guessing either the pot is flakey, or the solder joint to it are bad, or both.....
tapping the "H sync" pot on my test chassis, makes it flicker around in the H position.
 
OK i got the b+ up to 119.2v. The jitters were there on power up but are away at the moment. Will leave it on for a bit to see if they come back.
 
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