AD15 blew an EL84 then died

[Ade]

Hi

I know these posts are pretty common so I'll keep it brief. As the topic says my AD15 blew an EL84 then stopped working. I've replaced both EL84s with new ones and swapped the 12AX7s with good ones from my AD50 - but still nothing. Pilot light comes on but no sound at all. All valves glow and heat up including rectifier which gets hot (ouch!).

Before I go to a tech:
Is there an internal fuse I can check?
Is there a way of testing the rectifier valve (I don't have another at hand)?
Anything obvious I could be missing?

Thanks.

Ade.

[Ade]

Well I feel pretty silly! Found the fuse easy enough and yes it's blown. (I swear I looked before and couldn't see it from the outside - found from looking inside - what a twit!) Obviously went when the valve did. Now to find a replacement and see if that's all that's wrong.

EDIT: It appears to be a T250mA?



Ade

[Les Paul Lover]

At least your fuse is visibly blown!!!!!

When I had issues with the valve heater circuit in my AD15, the fuse failed too..... nut looked intact! Good thing I had a multimeter at hand.....

A shame you're in OZ, I have 9 of those fuses spare now - and I don't expect to use them all in my lifetime!!!

[Sooner]

EDIT: It appears to be a T250mA?

My AD15 calls for a standard 250ma, not a slow blow:

[Ade]

Thanks sooner. My amp has the same on the back; just says 250mA but the fuse that was in it has the T prefix, i.e. T250mA. Does the T denote slow blow?

Ant, what are yours?

Ade

[Jondog]

T is for time delay, so basically slow blow.

[Les Paul Lover]

Mine is the same.

It says 250ma, but the fuse inside was T250ma, and that's what I bought and replaced it with.

Since I've replaced the valve heater circuit (which caused the fuse to blow when it failed) it's been running fine and dandy.

[Ade]

Thanks fellas for all your help. I've rung around my local music shops, electrical retailers and repair shops and no one has a T250mA. Two only had 500s or 1s and one bloke looked at me like I was weird wanting a 250mA fuse. Are these fuses not that common or do I just live in backwater...?

Ade

[Les Paul Lover]

I got mine on eBay.

[Ade]

Hi all

Just a quick update. I found some fuses (ebay to the rescue) and my AD15 is back up and running. The failing EL84 must've taken out the fuse, and hopefully thats the end of it. Very happy to have my AD15 up and running again. Thanks for your help.

Ade

[Les Paul Lover]

Great news.

It is scary when they stop working, and such a relief to have them up and running again!!!