help with fender deluxe 90 dsp

[movek1]

hi, im new to this, not electronics but forums.
I have a fender deluxe 90 dsp, and it shuts on and off, not the power but the signal, it almost seem like with every strum of the guitar it cuts in & out, not a perfect cut but almost a sweep or slope, and its kind of random, and it does it within 30 seconds of the amp on.
If some one can help on where to start with diagnostic that would be very cool.

[Enzo]

Connect a different speaker to it - any change?

YOu have the preamp out and power amp in jacks on the rear. Plug a spare cord from one to the other. ANy help?

[movek1]

i was reading some other posts and problem solved, it was a bad solder joint at u10 heatsink.
thank you

[Enzo]

Darn, that was gonna be my next guess...

[movek1]

what does plugging a cord from preamp out to power amp in do?

[Enzo]

It bypasses the cutout contacts in the power amp jack. They are potentially a source of loss of signal. This is a very quick and simple test to find out if this common problem is what you have.