Fender Hot Rod Deluxe Reverb Drive Channel not working

[Perkinsman]

I know there are a number of posts made on the HRDR due to a variety of problems. I had some severe distortion/oscillation on all channels and replaced the 3-22uf caps and the 47uf filter caps with some F&T's and that stopped all the problems with the exception of the inability to engage the drive channel. When I push the drive button, the red led comes on, the drive volume works in conjunction with the master volume but it doesn't get 'dirty". It just stays clean.

I've ran the 12ax7s thru a tube tester and they all test fine. Would this be the drive button or one of the relays and if so, which one is the likely culprit?

[52 Bill]

If the channel is switching, then the problem may be in the gain setting fet.

I'm not in the shop, so I don't have copy of the schematic in front of me, but there is an fet switch that adds a larger value cathode bypass cap to one of the 12AX7 stages that help the signal to distort.

I'm sure that if you look at the schematic you will find it. Make sure that the gate voltage changes with the channel switch and that the fet turns on and off.

[glebert]

Is there a model called a Hot Rod Deluxe Reverb? There is Hot Rod Deluxe, and Deluxe Reverb. This sounds like a Hot Rod Deluxe based on your description, correct?

[TomCarlos]

I'm not sure if this makes a difference.... but when you say "pushed the drive button" ... are you talking about the button on the amp or the button on the foot switch?

[Perkinsman]

Could you please tell me what fet you're referring to on the board.

[Perkinsman]

I was wrong about the model, it's a Blues Deluxe....Anyway, back to the point. I'd like to know why there's no dirt when I push "channel select"?

[xtian]

Did you visually inspect the area on the PCB that generates +/- 15v for the switching system? This is the part that browns out from heat and fails on many, many of these HR models, including Blues Deluxe.

[52 Bill]

Could you please tell me what fet you're referring to on the board.

Sorry, that fet is not part of your amp.

When you switch channels to distortion, does the normal volume control have any effect on the signal level?

[glebert]

I was wrong about the model, it's a Blues Deluxe....Anyway, back to the point. I'd like to know why there's no dirt when I push "channel select"?

Original or Reissue? There are different schematics for them, but I have not compared. Not to be a crank, but someone asking for help and giving the wrong amp model is very frustrating to me. It makes me not want to spend any time trying to help you.

[The Dude]

Check plate voltages and/or plate resistors on preamp tubes. I find they commonly go towards open on these amps.

[Perkinsman]

Sorry, that fet is not part of your amp.

When you switch channels to distortion, does the normal volume control have any effect on the signal level?

No, the master controls the volume, the normal volume control is disabled.

[Perkinsman]

Did you visually inspect the area on the PCB that generates +/- 15v for the switching system? This is the part that browns out from heat and fails on many, ma of these HR models, including Blues Deluxe.

I visually inspected the 2watt resistors that typically open due to heat and the area is not showing browning. I'm not sure what components make up the "switching system". Where can I find the values of the TP's listed?

[Perkinsman]

Reissue, thank you for your help.

[J M Fahey]

Ok, we´ll wait until somebody uploads the proper schematic.

In any case, solving problems implies "troubleshooting", meaning reading the schematic, doing some tests, measuring voltages, etc.

It´s very unlikely that somebody says "oh, that one is easy, it happens all the time, just replace R301" or whatever.

Some people hope for "a list of common faults" to avoid troubleshooting and just go through it.
Think this way: IF there were a "common problem" that would mean a design fault and that would normally already have been solved at the Factory.
In a large serious Company such as Fender they test all products a lot before comitting to massive production.

[nevetslab]

Fender Blues Deluxe Reissue Rev A Schematics

Ok, we´ll wait until somebody uploads the proper schematic.

In any case, solving problems implies "troubleshooting", meaning reading the schematic, doing some tests, measuring voltages, etc.

It´s very unlikely that somebody says "oh, that one is easy, it happens all the time, just replace R301" or whatever.

Some people hope for "a list of common faults" to avoid troubleshooting and just go through it.
Think this way: IF there were a "common problem" that would mean a design fault and that would normally already have been solved at the Factory.
In a large serious Company such as Fender they test all products a lot before comitting to massive production.

Fender-Blues-Deluxe-Reissue-2004-Schematic-Rev-A.pdf