Triple rectifier no input or channel select.

[Dackenshire]

I'm new to the forum. My rectifier has been having issues with noise. So I bought a few new replacement mesa 12ax7 tubes .. while I was switching them out I had the amp in standby and pulled a 12ax7 and realized I didn't turn the power off only the stand by. According to the mesa trouble shooting video removing them in standby should be ok. Well I flipped it back on but the channels don't light up any more and won't switch with either the foot switch or the knob on the back. What's more, it no longer has input sound. So no guitar sound, but you can still here it buzz away. And you can hear the volume of the buzz swell on the master vol, the 2nd channel volume, and the fx loop volume if you turn them. It almost seems like channel 2 is active with no lights and the amp is not receiving any input. I have tried all the original tube and different variations of tubes and nothing is bringing the channel selected or input sound back. I'm afraid I bricked it somehow by trying to replace the tubes. Has anyone had a problem with getting input sound and not being able to select channels with the amp or pedal?

 

[3124+]

These symptoms indicate a problem with the +3/-3VDC supply. Bad diode or something.

 

[Dackenshire]

Any idea how much a repair might be if it's one of these things?

 

[3124+]

Probably not much $.

 

[Tatttfupfreak82]

My channel selector on back of amp doesn't work its stuck on
Second: not knowing what's going on I switched the bias switch from 6l6 to el34 I played for a few seconds and the amp on light went out it still has power but now only load humming noise. The channel light indicator is still on2 and I notice my 6, 7, 8 tubes alr not lit

 

[Tatttfupfreak82]

My channel selector on back of amp doesn't work its stuck on
Second: not knowing what's going on I switched the bias switch from 6l6 to el34 I played for a few seconds and the amp on light went out it still has power but now only load humming noise. The channel light indicator is still on2 and I notice my 6, 7, 8 tubes alr not lit

 

[domct203]

My channel selector on back of amp doesn't work its stuck on
Second: not knowing what's going on I switched the bias switch from 6l6 to el34 I played for a few seconds and the amp on light went out it still has power but now only load humming noise. The channel light indicator is still on2 and I notice my 6, 7, 8 tubes alr not lit

Switching bias to EL34 mode while running 6L6GC tubes most likely destroyed your output tubes and other components like screen resistors or power section diodes or bias section components. That is why there is a warning not to do that right by that switch.

It would be best at this point to bring the amp to a competent tech.

We all make mistakes... Mesa’s are tough amps, as long as there was a proper speaker load connected you are most likely out a set of power tubes and a couple hundred for tech bench time and parts.

 

[Tatttfupfreak82]

I have a warranty on it it even covers accidental would that cover it I'm on disability and scraped up every penny to get the amp

 

[Tatttfupfreak82]

Is there any chance it's just the power tools I've already ordered a new set which I was going to do anyways

 

[domct203]

If there was already a problem with the channel switching I doubt this is just power tubes. It’s possible that there is a bad preamp tube in there that is dragging down the power to the switching matrix, but we are just speculating.

Did the amp work correctly when you first got it?

I have no idea what your extended warranty covers, you’ll need to look into that.

Either way, at this point it’s probably best to get a tech involved, and pursue the warranty.

 

[domct203]

Is there any chance it's just the power tools I've already ordered a new set which I was going to do anyways

Wondering how you are making out with the amp? Have you had a tech look into this?