No output from 1964 Deluxe Reverb - Help!

[Josephcarassojunior]

Hi all, played a gig w my Deluxe Reverb (1964). Brought the amp back home where it sat for about a month. Tryed playing it yesterday and almost no volume comes out it. If i crank up volume knob guitar can be heard low and distorted. Issue happening in both channels. Changed all tubes, issue persists. Tried external speaker, same issue. Reverb and tremolo can be heard /seen to be working. Any help most appreciated!

Txs,
Joe

[Leo_Gnardo]

It's going to take a trip inside - I'll bet some wire or component has come unstuck. One of the most common trouble spots in old Fenders, and one that would cause the symptom you describe, is a disconnected feedback node resistor. In a Deluxe that's a 47 ohm resistor located sideways on the board, just behind the vib. channel's bass pot. For reasons I cannot fathom, one end or the other of this resistor loosens up. OR the wire from the board to the brass ground bus, same location, that wire comes unstuck & then you have practically no volume.

Of course it may be something else, but given your symptoms, that's my best guess. Good luck!

[Josephcarassojunior]

It's going to take a trip inside - I'll bet some wire or component has come unstuck. One of the most common trouble spots in old Fenders, and one that would cause the symptom you describe, is a disconnected feedback node resistor. In a Deluxe that's a 47 ohm resistor located sideways on the board, just behind the vib. channel's bass pot. For reasons I cannot fathom, one end or the other of this resistor loosens up. OR the wire from the board to the brass ground bus, same location, that wire comes unstuck & then you have practically no volume.

Of course it may be something else, but given your symptoms, that's my best guess. Good luck!

Many txs for the reply. I am not amp savvy but will try and have a look once i build up the corage to open it up. You dont think it could be a blown transformer? Any other tests i could do without opening the amp? Many txs!

[rjb]

Many txs for the reply. I am not amp savvy but will try and have a look once i build up the corage to open it up. You dont think it could be a blown transformer? Any other tests i could do without opening the amp? Many txs!

The car guy says its probably a loose hose, and you're hoping its a blown head gasket!

[Leo_Gnardo]

You dont think it could be a blown transformer?

Crikeys, that's the #1 thing most folks come up with. If your car was sitting for a month then doesn't start, is the engine shot? Not. Likely.

9 screws and a view, doesn't take much to have a peek inside.

Replaced tubes, tried another speaker, you've already done everything you can externally. Time to go in. This isn't rocket surgery.

Of course there are lots of unscrupulous "techs" who would take you up on your "blown transformer" comment, then replace expensive parts unnecessarily and charge you a fortune. We try to avoid that scene here. In fact it's rare that transformers go bad. And your amp was working fine last time you used it, evidence the transformers are just fine.

[Jazz P Bass]

Devil's Advocate: it could be the OT.

The only way to know is to test the amp.

[Josephcarassojunior]

The car guy says its probably a loose hose, and you're hoping its a blown head gasket!

😂😂😂

[R.G.]

The advice here is very accurate - it ***could*** be a blown transformer, but it's almost certainly not that. Transformers don't die when sitting un-powered, at least not for the time you're describing. They die at inrush/power-on, or when they're very hot. And people do tend to immediately say "it's the output transformer, isn't it"" for reasons I can't fathom. Perhaps it's like going to the doctor for a pain in your gut, sure it's cancer when it's really indigestion.

As another vote, you're going to have to look at the insides of the amp, and almost certainly while the power is turned on in the open chassis.

Actually, I have slightly different advice. Needing to be told and reassured that internal diagnostics are needed is an indicator that you may not have the electronics skills and experience to work inside a live amp chassis. Unless you already know how to do this without killing yourself or worse yet further damaging the amp ( ), take it to a competent amp tech. This could and probably will be faster and cheaper than the learning you'd have to do to do it yourself, unless you already know how.

[Dave H]

It's not something daft like having the speaker connected to the external jack socket is it? When you tried an external speaker did you also have the internal speaker connected?

[Josephcarassojunior]

The advice here is very accurate - it ***could*** be a blown transformer, but it's almost certainly not that. Transformers don't die when sitting un-powered, at least not for the time you're describing. They die at inrush/power-on, or when they're very hot. And people do tend to immediately say "it's the output transformer, isn't it"" for reasons I can't fathom. Perhaps it's like going to the doctor for a pain in your gut, sure it's cancer when it's really indigestion.

As another vote, you're going to have to look at the insides of the amp, and almost certainly while the power is turned on in the open chassis.

Actually, I have slightly different advice. Needing to be told and reassured that internal diagnostics are needed is an indicator that you may not have the electronics skills and experience to work inside a live amp chassis. Unless you already know how to do this without killing yourself or worse yet further damaging the amp ( ), take it to a competent amp tech. This could and probably will be faster and cheaper than the learning you'd have to do to do it yourself, unless you already know how.

Txs for the reply. Indeed i have never fixed an amp myself, other than changing tubes and fuses. But as i am currently living in Africa, without a technician within thousands of miles, it may be worth opening and checking for obvious loose wires... Lets see...

[Josephcarassojunior]

It's not something daft like having the speaker connected to the external jack socket is it? When you tried an external speaker did you also have the internal speaker connected?

I tried the external speaker without the amps speaker connected, first through the normal speaker jack, then through the external speaker jack.

[Dave H]

I tried the external speaker without the amps speaker connected, first through the normal speaker jack, then through the external speaker jack.

It should have worked through the normal speaker jack but not the external jack because the normal jack shorts the output if it isn't used.

[R.G.]

There are always special circumstances. You do have a valid reason for your post and approach. There are many many posters here with a tech just across town that don't want to bother taking it there. We feel an obligation to protect them from electrocution.

As I do for you. Be advised that you are taking a chance on your life if you ever open up the amp's chassis and mess around inside it with the power on or even newly turned off. So only take the chances you are willing to die for there. You have been warned.

If you can find a broken wire, great.

You say this is a 1964 model. Has it ever had its capacitors changed?

Do you have access to a multimeter?

[Chuck H]

I'm with R.G. (just see my sigs )

Just take the amp to a tech. DON'T say anything about transformer concerns. Just tell them what happened. Unless you want to learn about working on amps (and you seem apprehensive) this is the easy thing to do and it shouldn't be expensive to get a diagnosis. The old Fenders are usually in need of:

A cap job (replace all electrolytic capacitors).
Check resistors for drift and caps for leakage.
Clean any non soldered contacts. Switches and jacks.
Check tubes and bias. Replace, adjust as needed.

Provided nothing catastrophic is wrong (very unlikely) it'll cost between $150 and $300 depending on what the tech learns. It's cheaper to do it yourself, sure. But it comes with the possibility of additional problems and many hours of correspondence here. It's always difficult to handle this sort of thing remotely and while a tech with experience can work in your amp like dinner at the kitchen counter, you can't and mistakes happen. So...

If you WANT to learn how to work on your amp, you can do that here. If you don't want to spend many hours at this I would suggest finding a competent amp tech.

[Enzo]

If you are living or stationed a thousand miles from anything, how do you communicate? Radio? And if so, who fixes your radios? This amp may not be a radio, but electronics is electronics, and a competent radio technician, or oil rig controls engineer or any other electronics guy, should be able to get through it. Especially if he can communicate with us as you do.