Amplifone HV board melting caps !!!

JDGJr

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See photo where both caps near CR6 are melted or discolored!

the one with the split casing was much closer to the resistor when i found this condition. The video was working, with this cap, but i wasn't able to dial in a good display.

Is this common? Is there anything I can do when i replace the caps to keep if from happening again?

thanks for any input
 

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Thanks for the postings related to this. Have the info i need to get the parts to do the mod.
 
Thanks for the postings related to this. Have the info i need to get the parts to do the mod.

Your HV board is of a different revision than the one shown in the document... I don't believe CR5 or CR6 are part of your PCB layout... they have been most likely added later to the underside of your board...

I should update that document to cover older versions of the HV board.
 
Here's a pic of the underside of the board, after i removed the original resistors. Ignore the red wire- that's for a different fix.

So i think i need to bring do all my wiring on this side, but i'm a bit confused where each of the 4 legs get wired to.

Saturday 1/08: my previous drawing was obviously wrong, I updated it here. Can someone confirm that the blue lines are correct?

thanks,
John
 

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Got this all put back together - video is looking great, and the heat sink is relatively cool. progress all around!
 
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