G07 with "wandering" B+

Peale

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G07, newly rebuilt. B+ won't stay in one place. Goes as high as ~121VDC, or as low as 88VDC. Picture is pretty good. Voltage changes on brighter or darker images. Darker images = higher voltages, and vice versa.
 
Sounds like cold solder. Normally cold solder joints are found on R101, and any of the power resistors...
 
I did not. And something I neglected to mention earlier was that I don't have a fuse in there, I'm using a 100W light bulb in place of the fuse. It's pretty dim except when there's a darker screen, then it brightens a bit. Not super bright, but bright enough.

I've got another G07 I can scavenge the C1106 from until I can pick them up. Any way to test to see if it's bad?
 
You can do diode tests between all the legs to check for shorts or bad readings.

And I'd put a fuse in there. The bulb might be enough of a load to pull down the B+...
 
It blew the first time I fired it up - blew black. So after replacing the HOT I replaced it with a lightbulb. If they were regular fuses that would be one thing, but pigtail fuses are a PITA to replace.
 
You need Bob's fuse circuit breaker. Connect it up and it pops the breaker instead of the fuse. Helps you troubleshoot without going thru a bunch of fuses. Just push to reset and try again...
 
I was going to make my own, but wasn't sure which circuit breaker he uses.

Made me go pull mine to look. Numbers on it say:

BC62
2.5A 250V~1
1K19

Has two wires attached with an alligator clip on each...
 
Just put two alligator clips on some wire and solder the ends to a fuse holder. Not as good as a circuit breaker, but you can easily change the fuse.
 
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