Fender Champ XD No Output

[Pryde]

Hello. I have a Fender Champ XD/. It powers on but no output at all and also channel switch/LED doesn't function either.

Schematic:
http://support.fender.com/schematics..._schematic.pdf

The signal is lost somewhere in the solid state preamp section but not sure where or how to isolate.

I have strong signal at pin 7 of U7-B op-amp but a super weak signal at pin 5 there (maybe this is normal)?

Jumping up ahead I have no signal at R18 (+ out) or R19 (- out).

I appreciate any guidance on how to troubleshoot this one. Thanks

[52 Bill]

Jumping up ahead I have no signal at R18 (+ out) or R19 (- out).

That point of the circuit is just after the DSP that is not shown in the schematic, so the signal is dying either just before or inside the DSP circuit.

If you have signal at pin 7 of U7 then the problem would be on the DSP board.

[Pryde]

That point of the circuit is just after the DSP that is not shown in the schematic, so the signal is dying either just before or inside the DSP circuit.

If you have signal at pin 7 of U7 then the problem would be on the DSP board.

I feared as much. So this one goes to amp heaven. I might offer the guy a little $ and use the cab/chassis/speaker for a build.

[52 Bill]

I feared as much. So this one goes to amp heaven. I might offer the guy a little $ and use the cab/chassis/speaker for a build.

But, there's more!

I assume that you have tested the power supplies? There are +&-12 volts for the op amps and there are 5vdc and 3.5vdc for the DSP board.

Then there are all of those plug in ribbon cables, etc.

And I suppose you could find out if the DSP boards are still available from Fender.

And this had a 5 year warranty, is it the original owner and how old is the amp?

[guitardad]

Try reflowing the solder on the DSP IC with hot air station or small tip pencil..

If it is under warranty, get an RMA

[Pryde]

Amp is not under warranty (2006). It appears Fender does not sell just the DSP board. All through hole ICs have correct +/- 12v voltage. Not sure of voltages on DSP yet??? I don't have a hot air station so no SMD soldering happening here. As I last resort I could try a pencil solder across the pins but don't want to go there yet.

It appears these DSPs go south on these amps and fender just issues a new amp if under warranty. They do not repair them. If not, then well...

[Pryde]

Just an update. A very nice fellow at Fender support is going to send me a "pull out" DSP board from an otherwise shot amp that is in the recycle bin there. It is certainly worth a shot to throw in a new pcb and see what happens. Problem is he isn't sure if the pcb is good or not but I appreciate the gesture nonetheless.

[dbtech]

Hi just joined, so sorry for the delayed response! I had this happen on our Worship Leader's Super Champ XD. I bypassed the DSP board and turned the amp into an analog only (no effects) box, but it works fine. I used less than $5 in parts. We ended up with volume and brightness controls (you'll need external pedals for the effects). So many people have run into the failure in the DSP board that I wrote up the procedure. If you still have the amp and have some tech skills, you can probably do it yourself (otherwise pick a friend who owes you!). Here's the sheet: http://brasherweb.com/techfiles/Fend...bypass_mod.pdf