Any Fender Gdec people out there?

[tdlunsfo]

I have a Gdec 30 that goes into reboot loop after being on for about 15 mins. Appears to be heat related. The +/-5v regulator heat sinks are very hot. Strangely still has stable 5v while in reboot loop though. Still have 3.3v regulator as well. Not sure. Anyone have experience with these?

[The Dude]

Can you upload a gutshot picture? I believe I worked on one of those a while back and the only thing that worked was adding heatsinks to the regulators. I'm not sure I'm remembering the right amp, though.

[tdlunsfo]

Sure.

[tdlunsfo]

First picture is the regulators in question. They are on heat sinks but they are small. Appears to be a few other regulators middle of the board with no heat sinks. I can blow my heat gun in the vicinity of the rectifier diodes/5v regulators in first pic and reproduce the fault. I just don't see anything abnormal with the voltages. It's almost like it is just poorly designed and there is no airflow. The chassis is completely enclosed with the back of the amp on.

[The Dude]

That's not the amp I was thinking of, sorry. It may still not hurt to heat sink those regulators. And, I'd be suspect of any electrolytic caps that are right next to hot regulators.

Edit: <simulpost> My heat sink suggestion was directed at the regulators in the middle of the board. If those aren't getting hot, no worry.

[tdlunsfo]

No worries. I checked the ESR of those and they were good with values spot on 1000uF. But I hear you..not the best setup there. I'm thinking about adding a cheap fan and calling it done.

[The Dude]

Did you check that little C49 right next to the heat sink?

[tdlunsfo]

ESR is good but measures high. It has a little .1 smd cap soldered across the terminals. I can attempt to replace it.. should be fun with this smd cap. I did find a schematic with a bunch of test point. Will try that out later.

[tdlunsfo]

Cap was good. Ended up replacing both 5v regulators and seems to have solved the problem.