G07 keeps losing focus

boganvilla

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I have a G07 chassis that seems to take forever to get a fully focused picture.
I have attached pics showing the progression of what it looks like.
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I have tried this chassis in other games and get the same result. A known working G07 works fine in the game so I have ruled out the tube as well. I have also swapped out the flyback with a known good flyback yet still get the same results.

Funny thing is if I turn the game on after not being on for a while it takes forever to get a focused picture. Yet if I turn it on after its warmed up it still takes a bit of time to get a focused picture but nowhere near as long if it was a cold start.

I'm not sure what to try next so any help would be great.
 
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Is the B+ set at 120v? Maybe its has a flakey pot and starts low then eventually drifts up to 120? Put a volt meter on it and watch the B+ as you turn it on and see what it does....
 
Ok. So I changed the cap on the neck board an re-flowed the solder on the focus wire at both ends (Socket and flyback) and the issue persists.

I measured the B+ and was getting a stable reading of 140V. I cannot turn the B+ voltage down any further as the adjustment is maxed out.
Would the B+ being too high cause this or am I looking at the wrong place??
 
It's definitely on the neck board. I swapped the neck board and it was all good.

I have a sneaking suspicion it is the socket in the neck board. I will swap that out with a spare and report back.
 
I had a similar issue, it was the focus wire from the adjustment pot to the neck board. I snipped off the end of the wire resoldered it and it's good to go now
 
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