Pro Jr Build - Blown Fuse on Startup

[trevorpowell]

Hey Everyone,

 I just took my first crack at building an amp by following the Pro Jr build/conversion. I finished it up last night, but the fuse blew on the first power up just a second or two after flipping the power switch (no tubes in at the time).
Is there an immediate jumping off point for troubleshooting? Or am I looking at a laundry list of potential issues?

Thanks!

[PRR]

Welcome!

Build a lamp-limiter!!

Disconnect parts of the power wiring in some logical order until the short is gone.

[trevorpowell]

Welcome!

Build a lamp-limiter!!

Disconnect parts of the power wiring in some logical order until the short is gone.

I'll give that a shot, thanks!!

[trevorpowell]

 Well, before building a lamp-limiter I was able to track down some problem areas where components were touching the chassis beneath the board (rookie mistake not trimming those up properly). After correcting those, I tossed in the original fuse and the amp fired right up. The amp stayed on plenty long enough to check biasing, add in tubes (which lit up - the 12ax7's dimly albeit), and try to get sound.
 However, I was only getting a very faint hum out of the speaker regardless of where the volume knob was set. I turned the amp off to double check components, connections, etc. then it immediately blew the fuse the next time I turned it on.
 Obviously there is another undiscovered short, but are there specifics I should be looking at to resolve the no sound issue? Prior to the rebuild I had some bizarre issues with sound, so I'm wondering if I'm looking at some sort of transformer issue - again I'm awful green behind the ears, so it's all a mystery to me.

Thanks!

[scstill]

follow this
https://robrobinette.com/Tube_Amp_Startup.htm