So Mesa told me.......FIXED

[R_ADKINS80]

....when I first bought my TR last Feb. that it was perfectly ok to use the Bold/Spongy and Diode/Tube switch while the am is on. This is the way I have used them since. Tonight I go to flip to Spongy mode for some squishy goodness on some neck pick-up heavy vibrato licks and I get a loud pop, amp shuts off, smells like a fried Rockford Fosgate am at an SPL competition and the fuse IS NOT BLOWN. WTF? I thought maybe I had a rectifier tube go bad on me so I switched em out.....nothing......set it to diodes and pulled the rectifiers and nothing. Calling boogie tomorrow, any ideas in the mean time? Also I have switched my power tubes and preamp tubes out to rulle anything tube related out and got zero results.

Boogie-less

 

[Koreth]

If I had to guess, I'd say there was a surge when switching, and said surge fried a component, be it a capacitor, diode, resistor or something else, somewhere inside the amp's power supply. Though you say the fuse is not blown, did you try replacing it with a known good one anyway? In my experience, fuses can sometimes be blown, but the way in which they blew makes it very hard to tell if it actually blew or not upon visual inspection.

IMO, you'll probably have to take the amp to a tech.

 

[R_ADKINS80]

The fuse has continuity on my Fluke meter.......???

 

[c.t.d-nicke]

smells like a fried Rockford Fosgate am at an SPL competition

blown caps smells really bad

nicke

 

[fluff191]

Wow thats very strange. I have never had a problem switching back and forth on my Dual Recto.

 

[R_ADKINS80]

Niether have I the entire time I've had the amp since last Feb.

 

[R_ADKINS80]

This makes 3 heads that have blown on me at slightly above bedroom level volume in the last 2 years. The transformers blew on me twice with my Randall V2 and now my mystery melted Boogie. I need to switch instruments to maybe the washbord or the one string wash tub and broom stick upright bass.

 

[nemesys]

Mesa amps have varistors in the power supply for surge protection, which can blow like that when they overload. If your house current was running a sustained current that was just ten or fifteen volts high, it could happen. This is actually good, because blowing a fifty-cent varistor is better for you than melting a $200 power transformer.

The varistors look a lot like disc capacitors, and will be near the amp's power input. Something to check, anyway. Check your wall voltage while you're at it.

 

[R_ADKINS80]

Yeah wall voltage is was good at the time of the problem. I made sure to check that while I had my meter out. I'm not really wanting to open my amp up because won't that void my warranty?

 

[Octavarius]

Yeah wall voltage is was good at the time of the problem. I made sure to check that while I had my meter out. I'm not really wanting to open my amp up because won't that void my warranty?

You can open the amp up without voiding the warranty. Take a look inside without touching anything and look for burned/fried components. However, easiest thing is to call Boogie, explain everything. Having had a peek inside might help troubleshooting with them, though.

Voltage might have been good, but you'll never know if there was a spike or a surge at that particular moment your amp blew. Get a good power conditioner (Furman)!!!

If this is your 3rd head to blow like that, something must be wrong with the power in your house. It's definitely not normal for amps to do that. So again, I highly recommend a power conditioner! It'll save you a lot of this kind of trouble.

 

[R_ADKINS80]

The bown Randalls happened at another location.....I called boogie this morning so I hpe to hear from them this afternoon. I have been meaning to get a power conditioner and a good surge protector....I guess now I have real motivation to do so.

 

[R_ADKINS80]

Just got off the phone with Chris at Boogie. He told me to put a different fuse in it just to rule it out. I had no spares so I picked some up at lunch earlier today anyways. He also told me that I could open my amp up no problem and not mess with the warranty as long a I don't mess with any of the internals. He things a shorted power tube could have taken out a screen grid resistor. I was looking right at the back of the amp when it happened and saw no "light show" coming from any tubes or anything. It just popped through the speakers and powered down like someone hit the power switch. I will stick a fuse in when I get home and take the amp chassis out to examine the resistors in question. If no luck I got the number to the local repair center not 15 minutes from my house.

 

[thunda1216]

a bad rectifier tube will cause this type of problem, even with the switch set to solid state rectifier if your amp has this option.

ty

 

[R_ADKINS80]

Ok well the fuse didn't fix it, as I thought would be the case. But I did it just because Chris told me to rule that out. I then took his advise and pulled the amp out to get a really good look inside. I found no burnt grid resistors or even the slightest discolorations of ANY components/circuitbords. I did rule out my power cord because I was reading full voltage at the amp end of it, however, when I plugged it into the head and turned the power switch on i was reading only 3VAC at the fuse......I believe it might be a fubared power plug at the back of the amp or a bad power switch. At any rate I gotta take it to the Repair shop next week unless they have hours on saturdays.

 

[R_ADKINS80]

Faulty power socket on my head. No blown fuses, grid resisters or anything.

 

[Elpelotero]

Glad you got it fixed!