blew my head, but dont know whats wrong with it. help?

[kernelxsanders]

so i was at band practice the other day, and i was playing through my old crate head, and it started smellin funky, got really hot and just stopped producing sound all together, so i checked the fuse, and the fuse is fine. does anyone have an idea as to what could be wrong with it? id like to get it fixed but i dont feel like paying someone else to a job i could do myself.

also, while im on the subject, the same thing happened with a little 2x8 amp a while back. it was plugged into a cab as i was recording something (this was before i had any knowledge of anything having to do with recording music) and the input jack started smoking and it hasnt worked since. but i cant find a fuse anywhere on the amp, so i have no clu whats wrong with that as well.

but i would like to fix both amps, but i do not know whats wrong. can anybody help me?

 

[bryan_kilco]

Did you open the amp up and take a peek around inside? There is most likely internal fuse(s) inside as well as a main fuse on the outside.

 

[if6was9]

You may have burnt out a chip if there was a burning smell. Seen it happen a couple of times with active monitors and combos.

 

[Omega_Void]

...my old crate head... started smellin funky, got really hot and just stopped producing sound all together...

Okay, no sound -- but did the power light on it go out, or did it stay lit?

Also, are they tube amps or solid state? "Old Crate" and "2x8" gives really no clue about what sort of circuitry you're talking about.

The fact it's happened to two amps may just possibly be significant. You're not using a guitar cable as a speaker cable are you?

...i dont feel like paying someone else to a job i could do myself.

...but i do not know whats wrong.

Well, provided you know what you're doing you could open 'em up and take a look. Failure accompanied by funky smells/smoke often leaves visible residue/charring/melting. Knowing what components failed will help in figuring out why it happened.

 

[kernelxsanders]

Okay, no sound -- but did the power light on it go out, or did it stay lit?

Also, are they tube amps or solid state? "Old Crate" and "2x8" gives really no clue about what sort of circuitry you're talking about.

The fact it's happened to two amps may just possibly be significant. You're not using a guitar cable as a speaker cable are you?



Well, provided you know what you're doing you could open 'em up and take a look. Failure accompanied by funky smells/smoke often leaves visible residue/charring/melting. Knowing what components failed will help in figuring out why it happened.

the light comes on on both amps, just no sound. and to be more specific, the crate is a solid state GT1200h and the 2x8" is a Traynor TRM40. and when the combo was plugged into the cab, i cant remember if it was a guitar cable or not, with my little knowledge at the time, it probably was.

i also have not tried, looking inside either of the amps, but ill do that soon so i can try to see exactly whats wrong. while im at it, i can also go ahead and fix my other instruments

 

[BLUElightCory]

Are you using an appropriate speaker cable?

 

[Omega_Void]

Solid-state amps then. Parts will be cheaper than a tube amp, but are you sure they're worth repairing?

Two dead amps could be a coincidence but it's more likely the cause of failure was the same in both cases. In which case replacing the blown components is not going to be a long-term fix unless you can eliminate the cause of failure.

the light comes on on both amps, just no sound.

So the power supply is giving some voltage at least. If there's no sound at all then, the failure is in the audio chain.

Blown power transistor seems most likely, what with the overheating and the smoke.

i cant remember if it was a guitar cable or not, with my little knowledge at the time, it probably was.

Well that's one thing you definitely don't want to do.

There's the possibility of excessive current heating the conductors and melting the insulation, which will short the output.

Also the capacitance between the signal conductor and shield can promote the poweramp to go into oscillation, which can heat the power transistors up pretty badly, even if the cable remains intact.

You could maybe see if there's signal coming from the "line out" jack on the TRM40, and from the "insert" jack on the Crate if you have the stereo-to-mono cable it needs. If you have output here, then you know the preamp section is functional. But it's better to have a look inside before you switch the amp on again or you might make the damage worse.

 

[kernelxsanders]

thanks guys for all your help so far. im pretty tied up at the moment so i dont know exactly when i can take the time to look further into fixing them, but when i do, ill keep this thread updated!