Marshall 9005 blowing fuses one side.

[Neale Dunham]

Hi guys anyone got any ideas on this one?

So, I got a Marshall 9005 the blackface 3u monster.

Its a dual bloc amp

The right hand side works fine but the left takes out the T5 fuse every time.

I swapped the valves from the left to the right and all works well so I guess I can eliminate valve failure at least.

Ive also checked the circuit board underneath and can see nothing obvious like dry solder or burnt resistors etc.

What does that leave me with?

O/T failure or capacitors perhaps?

I'm not sure which way to take it?

If anyone has had similar issues with this amp or maybe knows a thing or two please shout up.

Many Thanks.

 

[johan.b]

Here is a link to the schematic
https://drtube.com/schematics/marshall/9005.gif

Sounds like a diode failure more than a cap or tranny to me

tell us more how the failure happened... any symptoms before failure? Does it blow the fuse without tubes installed too?
J