mark iv just blew :'(

[chris_EIT]

so I was playing as usual, and all the sudden, weird harmony effect, crackling sound and terrible smell. I just turned it straight off. wat the hell do I do? the fuse is fine, but the lights went very dim on it wen the change occurred. I was using it on full power with the volume on 2.

cheers guys,
I hope I can fix this, im on the verge of tears lol my poor baby

ps. tubes LOOK fine from my view, should I try it on tweed pwr?

 

[acorkos]

amps usually don't smell when just a tube blows. something inside the chassis cooked....hopefully you had just a resistor burn....worst case, you may have lost a transformer (unlikely, though).

 

[chris_EIT]

Ok, well despite my better judgemen, I turned on the amp, but I turned everything off that i could ran it straight connected on tweed power class a and so on, weakest power etc, it simply put out a static sound and smelled again, I'm going to take it to an amp tech asap, unfotunately so close to christmas I'm not sure I can get it looked at soon
Bugger

I HOPW it's just a resistor or something. Any chance it might be the caps? The amp is an A model, serial 1280

So yeah, pretty darn old :S

Cheers again

 

[Tuna141]

Don't worry too much...

The smell is most likely due to a resistor blowing after a power tube went bad - not that uncommon.

Odd are that a tech will have you up and running quickly at a minimal cost.

Good luck.

 

[Platypus]

Yes, it's quite strange that the fuse is OK... check to make sure the fuse is the proper rating for the amp.
It sounds like you had a power tube failure and it cooked some screen grid resistor(s) but it's hard to make a proper diagnosis based on the information without seeing it.

Make sure that fuse is the proper rating... someone decided to put a 10A fuse in one of my C+'s :shock:
Good thing I found it before anything terrible happened. :roll:

 

[6L6C]

Probably a cap and they do smell bad when they go

 

[chris_EIT]

cheers guys. u give me hope haha. well after more chat with friends who know amps their bet is a cap or resistor. ill get it looked at b4 new year though. how can I boogie wit out my boogie ;p

 

[chris_EIT]

how can I boogie wit out my boogie ;p

it's called Marshall, like all the major rock stars...

I think ill just use my bugera for now hehe

 

[Dutchman]

maybe???

http://forum.grailtone.com/viewtopic.php?f=3&t=31229

 

[chris_EIT]

ok the mark iv is in the shop!!! more details soon, I hope its nothing major :s

 

[ajtooke]

Same thing happened to my ~1993? Mark IVA head. Just hadn't been maintained like it should have and a power tube redplated and blew a resistor. I think it came down to dirty tube sockets.

 

[chris_EIT]

Woo!!! Just got it back! Turned out to be a few diodes. It's now back with a full service! Only cost me $150
good times

 

[6L6C]

Hey Chris
Good to here it was something that was relativity painless. A little good holiday news.