bad buzz man

[rocklander]

about 20some years ago a mate of mine was off to england for a wee while and he asked me to look after his roland 15watt practice amp (we thought it was the shizzle at the time) and he'd pick it up when he comes back.
seen him once since heh then, and he's not coming back me thinks.
anyhoo.. I've been using it as my main testing amp for when I build effects, and it's been ideal.. portable, inexpensive, solid state so nothing has ever gone wrong with it (bar the typical rotorua sulphur pots).. till last night..
I turn it on and just get a bad buzz.. sounds kinda 50hz, but very loud (not background noise, but all that I can hear from it). if I leave it on for more than a few seconds I blow the 500mA fuze

it's been great until now, and really not worth sending in for repair.. I guess I'm asking if there's any simple place to look initially to troubleshoot?
I suspect I ended up getting confused with my array of alligator clips for testing a boost pedal I'm making and ended up throwing 9VDC to the input... that likely to create this kind of noise?

[Rog]

Could it be a smoothing cap broken off?
That's a common fault.

[rocklander]

and hey.. there's none more common than I will look for loose/dodgy caps then. cheers

[heavyneeerd]

sorry a little off topic but for an fx loop can i use unsheilded cables ie: speaker leads?

[ant]

^^ no use shielded unless you want to pickup buzz.

I dont think it will be a broken off part.. more likely something shorted, would help to have a meter to check resistance to ground.

[hamo]

sorry a little off topic but for an fx loop can i use unsheilded cables ie: speaker leads?

Slight threadjack: what's your Dime Crybaby like?

[heavyneeerd]

its heavy, camoflaged, and awsome!!!!!

big range of sounds too
and a switch for 15db boost

very cool pedal makes me sound like i can solo now too

ps; won't be using the fx loop on the JVM as it cut out halve my volume even with the dbboost on.
when set to wet too quiet
when set to dry no more wah
works just fine in the front

[hamo]

its heavy, camoflaged, and awsome!!!!!

big range of sounds too
and a switch for 15db boost

very cool pedal makes me sound like i can solo now too

ps; won't be using the fx loop on the JVM as it cut out halve my volume even with the dbboost on.
when set to wet too quiet
when set to dry no more wah
works just fine in the front

Cool, thanks man. Tossing up which wah to wuy, er buy.
</threadjack>