Deluxe Reverb Reissue Vibrato Not Working

[kealonnix]

Hey guys, I went to sell my Deluxe Reverb today and was testing it out before I left the house.  Found out the vibrato does not work, so I had to cancel the sale.  I can turn the vibrato on via the trs foot pedal and I can hear oscillation and the speed change when you turn the knob, but there is no affect on the guitar tone.  The reverb works fine.  I tried a different pedal, same result.  I tried swapping around 12ax7s, same result.  I really don't want to crack this one open to work on it.  Does anyone have any suggestions or have seen this problem before?

[HotBluePlates]

This is a real Fender Deluxe Reverb? You didn't do anything like disconnecting the trem roach to increase gain, did you?

[kealonnix]

Yeah, it is a real Fender.  I haven't had the amp long at all.  I got it in a trade.  I never played the vibrato, just wanted to test it before selling it.  So, I know nothing about the history of this amp.

[sluckey]

Most likely a bad roach. OP1 on the schematic.

[kealonnix]

Pretty easy to replace?

[sluckey]

That depends on your skills and experience. It's located on a big, fragile printed circuit board. There's a lot of stuff to disconnect just to raise the board to gain access to the back side so you can do the soldering. So, take your time, be careful, and label stuff that you disconnect. Taking pictures before beginning might be a good idea. Be sure you get the new roach installed correctly because the only way to test it will be after you reassemble everything. It will likely take 15-30 minutes to raise the board and 5 minutes to actually replace the part.

[Fresh_Start]

Not trying to be a buzz kill but going inside modern Fender amps is not trivial. Sluckey's "fragile" is an understatement. If you are experienced at troubleshooting tube amps and soldering PCB boards, then it's worth the risks. Just be aware that the ribbon cables between the main board and the tube socket board are problems waiting to happen, and you have to move the ribbon cables to get underneath the PCB. Cold solder joints are the norm.

It could work out fine for you. I've had really bad experiences with a 2001 made in Mexico Blues Jr. I went in to add adjustable bias and have been chasing cold solder joints and other gremlins ever since. I've built four amps from scratch and am hardly the only one to have trouble like that.

Good luck!
Chip