Amp dies after 15 - 20 minutes

Does it get hot in that amount of time?

 

If you have an active bass, check your battery.

Otherwise, unless you have test equipment and some knowledge troubleshooting audio amps, you are looking at finding QUALIFIED Hartke service.

 

Clean off the fan, make sure it's blowing air

 

The description sounds like a thermal-related failure, which might be from an element that’s gone bad and needs replacing by a pro, but *could* be cooling, so, yeah, check that the fan is moving air like it should.

 

Could be thermal related.
Solder joints can crack from repeated heating/cooling expansion/contraction.
A narrow crack that barely makes contact might become one that almost makes contact as the circuit board heats up.
Also could be related to crud in a multipin connector on a ribbon cable.
A tiny bit of Deoxit and working the connector in and out a few times can help that.
All in all, if it is still trying to work, it's probably not seriously fried.

 

Only time that's ever happened to me was with a Carvin head and it was a short in the fan. Cheap fix.

 

I would think it was what everyone is saying. But I have to throw his in (as per your description of issue)
I have a Roland cube that kept doing that and I went through the hole circuitry and found nothing, then for the fun of it I connected another speaker and wow no problems. Speaker was the issue.
I am not saying speaker is bad but just another thing to check?

 

if you have an effects loop on the amp and or a line in and line out with 1/4" jacks then use a 4" pedal board cable on the in out and sometime that will fix it.

 

I do that with an Ampeg VT60 that I use for Bass VI - the loop jacks bypass the issue (which I think is corrosion on those jacks).

 

Stick a fork in it. It's done.

 

If you have the ability, open he amp chassis and vacuum out the cooling path. The fan can suck all sorts of crud up which eventually restrict the cooling air flow.

 

It could be a cooling issue, but it could be any number of other things too.

 

Sounds like a thermal cutoff doing its job. Likely either a thermal switch (in which case you may be able to hear the click as it goes out and resets) or a thermistor (which operates on electrical resistance rising with temperature, which could explain the distortion before it goes out); I doubt any amp from this century has solder pots. Whatever mechanism it's using, it's overheating and cutting off to protect itself. If basic cleaning doesn't work, get thee to a technician.

 

Is it actually overheating or MIGHT it POSSIBLY be overheating? This has not been verified as the cause, therefore it can not be said with ANY certainty that it IS overheating.

What is a solder pot? I don't think you mean what it really is.

 

So it actually died in 4 years and 15 minutes...

 

A type of thermal cutoff, basically a type of fuse. Too much heat melts a bead of solder to break the electrical connection. I saw them on electrical gear in the US Navy, motor controllers for pumps and the like. "Solder pot" may not be their formal name, but that's what we called them anyway.