Dual Rectifier problem, strange problem

[Lrscka]

Hi!

I bought an used dual rec solo head 100w about three months ago. I tested it and it worked. At the time I bought it I didn't have a cab. I just bought a 4x12 Orange cab this week and I took the head and the cab to my bands rehearsal space.

I plugged the head to the cab, let it warm up for about 2min, then flicked the standby switch and just as I strummed my guitar first time, there was no sound.
Absolutely no sound.

I was a bit confused, I printed out the manual and read it thoroughly. I checked the tubes and the 5U4's were barely glowing.
Then I tried the diodes and it still didn't make a sound. I've gone through the basic troubleshooting many times.
This just doesn't make sense, it was just on my bedroom floor for about three months and suddenly something happened during that time. It has not been plugged in while that time and it has been handled with care.

TL;DR Tested the amp, bought the amp, didn't use it for about three months and now it doesn't make a sound.

So my questions are, Does anyone know what might be wrong with it? Is the problem in tubes, diodes or somewhere else? So if you know anything, please help me, I would appreciate it.

Thank you in advance.

 

[afu]

The 5U4's barely glow in mine, too.

You might need to clean the sockets, maybe. What's your setup? Just guitar and cord?

Have you pulled the tubes while they're cold and looked at them? In the preamp, V3 and V4 can occasionally fail. Replacing one tube with a known good one will help identify that. Aside from failure, sometimes re-seating them will help remake the connections if they're dirty.

Is the FX Send at halfway?

Did the seller mention an FX loop mod? Does the hard bypass of the FX loop make a difference? Patch the Send to the Return and see if that makes a difference, either.

 

[silentbob]

I'd spray the jacks with tuner cleaner and insert/remove the plugs 30 or 40 times.

 

[Blaklynx]

Very simple checks because you never know....

Since the cab is the 'new' item.....
Is speaker cable good? (Make sure it's a speaker cable, too) If this wasn't good, then your amp *could* be up for repair..... no speaker load can lead to blown transformers.

Is the cab wiring good? (you don't say if it's new, 2nd hand, if you actually tested before buying)


Next....
Is the guitar cable good? Bad cable = no signal.

Long shot and super-obvious....
Volume knob on guitar was up? There's no 'kill' switch on the guitar that was flicked?


Can you take the amp to a guitar store and plug into a cab? Do you have friends that can help with a cab, or if they have a combo, plug their speaker into your amp; you may need an extension lead or an adapter (1/4" female-female adapter)


In a nutshell and in no particular order:
1. Try another guitar (I say this because my 5-way switch on my guitar failed = no sound)
2. Try different cables (instrument and speaker)
3. Try different cab / speaker

-B

 

[Lrscka]

The 5U4's barely glow in mine, too.

You might need to clean the sockets, maybe. What's your setup? Just guitar and cord?

Have you pulled the tubes while they're cold and looked at them? In the preamp, V3 and V4 can occasionally fail. Replacing one tube with a known good one will help identify that. Aside from failure, sometimes re-seating them will help remake the connections if they're dirty.

Is the FX Send at halfway?

Did the seller mention an FX loop mod? Does the hard bypass of the FX loop make a difference? Patch the Send to the Return and see if that makes a difference, either.

My setup is just guitar and cord.

I haven't yet pulled the tubes or even touched them. But I think I'm going to have to try.

The FX Send is at halfway.

The seller said there were no mods made. The bypass of the FX loop doesn't make a difference.

I'd spray the jacks with tuner cleaner and insert/remove the plugs 30 or 40 times.

I'll try this.

Very simple checks because you never know....

Since the cab is the 'new' item.....
Is speaker cable good? (Make sure it's a speaker cable, too) If this wasn't good, then your amp *could* be up for repair..... no speaker load can lead to blown transformers.

Is the cab wiring good? (you don't say if it's new, 2nd hand, if you actually tested before buying)


Next....
Is the guitar cable good? Bad cable = no signal.

Long shot and super-obvious....
Volume knob on guitar was up? There's no 'kill' switch on the guitar that was flicked?


Can you take the amp to a guitar store and plug into a cab? Do you have friends that can help with a cab, or if they have a combo, plug their speaker into your amp; you may need an extension lead or an adapter (1/4" female-female adapter)


In a nutshell and in no particular order:
1. Try another guitar (I say this because my 5-way switch on my guitar failed = no sound)
2. Try different cables (instrument and speaker)
3. Try different cab / speaker

The speaker cable is new. The cab worked when I tried my friends Marshall cab with the cab, just to be sure, so based on that, I'd say that the cable and the cab are both good.

The guitar cable is good, I bought it at the same time I bought the cab and the speaker cable.

Volume knob of guitar was up and there is no killswitch in my guitar.

I'm most likely going to take the head to a tech if these advices given won't help. I have one friend that has also had a Dual Rec, he looked my amp and he didn't come up with any ideas about what's wrong with it.

So, I'm going to try these advices you guys gave me, if nothing works, I think the only option then is to take the amp to a tech.

Thanks to all of you for responding and being helpful!

 

[biddifour]

I bought a brand new dual rec and 4x12 cab this January. At the store, for the demo, there was a brief moment where there was now sound. The sales-girl swapped the cord and it started working.

Once I got home with the rig, I experienced the same thing and quickly found that the cable jack was out of the jack a half inch or so. When I plugged it back in, I noticed it didn't "click", and then I questioned myself about if it had clicked the first time I plugged it in a few minutes earlier.

So, I took the jack assembly out of the cabinet to view the back of it and it looked fine. Then, I watched the cable end slide in and noticed that it wasn't being held by the innerds of the jack. So I gently bent the "positive" thingie so that it would hold the cable end in place better. Enough so that it fit snug against the "neck" of the cable end, if that makes any sense, and was well again.

At least check how the cable fits in to the jack.

 

[TRENCHLORD]

Just for reference sake,,,,,,,if you haven't already been through it.

https://www.youtube.com/watch?v=wSl-l9aWDHw

 

[Lrscka]

I bought a brand new dual rec and 4x12 cab this January. At the store, for the demo, there was a brief moment where there was now sound. The sales-girl swapped the cord and it started working.

Once I got home with the rig, I experienced the same thing and quickly found that the cable jack was out of the jack a half inch or so. When I plugged it back in, I noticed it didn't "click", and then I questioned myself about if it had clicked the first time I plugged it in a few minutes earlier.

So, I took the jack assembly out of the cabinet to view the back of it and it looked fine. Then, I watched the cable end slide in and noticed that it wasn't being held by the innerds of the jack. So I gently bent the "positive" thingie so that it would hold the cable end in place better. Enough so that it fit snug against the "neck" of the cable end, if that makes any sense, and was well again.

At least check how the cable fits in to the jack.

I have to check this thing too, there is no "click" when I plug the cable in.

Just for reference sake,,,,,,,if you haven't already been through it.

https://www.youtube.com/watch?v=wSl-l9aWDHw

Yes, I watched this video, it didn't help though

But nevertheless, Thanks to you too!