Low Voltage on B+ after big blue replacement in Tempest.

JasoneB

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I replaced the "big blue" capacitor on a tempest machine, after putting in the new one I have low voltage (120'ish V) on the B+, that is with the pot turned all the way up.
I did try switching back to the old big blue, still the same thing.
Game powers on and seems to run ok with sound etc, but the screen is not full size, it is now squished down noticeably.
Hoping by following what I saw as a strong suggestion repeatedly to replace the cap I didn't end up messing up the transformer unit, maybe I'm just missed something?
 
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The big blue is only on the 10vdc unregulated line, IIRC. You more than likely blew a fuse or something.

I have done some videos on testing the power brick but Dokert 's is the OG

 
The big blue has absolutely nothing to do with the monitor.

First I'd check your brick, just make sure it's outputting 25VAC between pins 10 & 11, and 11 & 13. This probably isn't the issue but doesn't hurt to check.

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Next, pull your monitor out and start following @andrewb 's 6100 guide


The issue is most likely just on your HV board but you need to rule out the deflection board and transistors first.
 
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Recapped the HV board, all is good now.
 
I reflowed most of the connections, including the headers. Didn't do the flyback as it seemed solid. Several of the solder joints (deffinetly original) looked like a blind chipmunk did them originally.
Board is in good condition overall so everything should be solid now. Now to spend an hour or so running back and forth behind the machine to get all the alignments/color adjustments perfect.
 
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