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Help !!!!!


 :
4/25/1999 1:14 AM
Doug
Help !!!!!
Here I am, 1am on Sat nite. Finally finished my 5E3 sans cab!!! And I have no output. Double checked my wiring, RG's debugging page didn't help. Help, my wife wants her kitchen back!!!. Am going to call it tonite, will post voltages tomorrow. Any ideas? :(  
Doug  
PS. No fuses blown (120V 1.5 amp), Light is glowing, output tubes are glowing. Thank god there was no smoke!!!!
 
4/25/1999 3:22 AM
Doug
More Info
Can't quit!  
Htrs: ok  
5Y3: (only) p4 375VAC plate  
p6 369VAC plate  
p2 5.72VAC filament  
p8 0v filament  
I have the 5v heaters hooked to p2/p8 and a flying lead from 8 to + of first filter cap. All measurements referenced to ground. no other tubes in circuit.  
Doug
 
4/25/1999 3:22 PM
Brian

Doug:  
 
It sounds like you have a problem with your rectifier. Measure the DC values on pins 2 and 8 of your rectifier and post these. Maybe this will help.  
 
Brian
 
4/25/1999 4:00 PM
Doug

See above, It is a NOS Jan 5y3gt. I can't find where my B+ is disappearing, The tube should be good, right?  
Doug
 
4/25/1999 5:08 PM
Benjamin Fargen

Doug,  
If the correct AC is coming into the 5Y3 and there is no DC present......it has to be a shorted rectifier tube. If you don't have a replacement tube.......wire in SS full wave rectifier with some in4007's and see if you B+ appears.  
One more thing.....Do you have the center tap of you PT connected to ground?  
 
Benjamin.
 
4/25/1999 6:43 PM
Doug

Yes PT centertap is connected to standby switch, then to - of first filter cap, then to ground.  
Doug
 
4/25/1999 10:04 PM
Carlo

Unless I'm missing something here, the PT center tap should go to the neg. of the first filter cap, then to ground. Pin 8 of the 5Y3 (B+) should go to the standby switch. You can get the layout for this amp at...  
 
http://www.hoffmanamps.com  
 
Carlo
 

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