[Johnson] Viking II: Fuse blows when plate switch turned on (key up)

[WQ9E at btsnetworks.net]

Don,

One common issue is carbon tracks forming along the 5R4 rectifier bases and tube sockets which ultimately will extend to ground and will cause fuse blowing.

If you don't find an obvious problem, start by pulling the 5R4 tubes which will help you narrow down whether the problem is in the transformer rectifier area or if it is an issue with the rectified HV DC.  Resistance checks may prove helpful in trouble shooting, particularly the resistance to ground of the plate supply.

Rodger WQ9E

-------- Original Message --------
> From: dgbergmann at comcast.net
> Sent: Sunday, November 13, 2011 7:52 PM
> To: johnson at mailman.qth.net
> Subject: [Johnson] Viking II: Fuse blows when plate switch turned on (key up)
> 
> Would appreciate any advice about where to begin troubleshooting. Unit fuse blows immediately when plate switch is turned on with key open. 
> Don WA2TXQ 
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