50/50 tech question - blowing fuses

[lreese]

Got to fix a 50/50 power amp that all of a sudden started blowing fuses. Already swapped all of the tubes - still blows immediately when the power (not standby) is flipped. Using a 3A slo blo. Before I go out and start buying parts and popping more fuses, wondering if anyone went through anything similar - been out of the DIY amp fixing biz a long time.

I'm thinking the MOV has gone bad - Am I barking up the wrong tree? - seems like its either that, bad power transformer, don't think there's too much there, just the fuse, power switch and heater circuit. Any ideas? Thanks.

If its the MOV - what are the specs I need? Thanks in Advance.

 

[AudioMonk]

Hello. Replace fuse with the correct type, remove output tubes and turn amp on. Then let me know if it still blows the fuse and we'll go from there.

 

[crane]

+1.
If still blowing, remove the preamp tubes too and check.
Check also the connectors where all the cables from the power transformers are attached. If it's brown/black, then you have to remove those connectors and resolder each cable to the main board (or replace the 2 connectors if you can find them).
BE AWARE THAT THERE ARE LETHAL VOLTAGES INSIDE THE AMP, EVEN UNPLUGGED !