Gah! Please help me with my recto!

[playsguitars]

So I just picked up a nice Sonset Beach 2x12 cabinet and proceeded to plug in. The cab is wired at 8ohms and my mesa is dropped to 50W. So I call mesa and they tell me that from the amp 4ohms into the 8ohm cab would be safe and even the prefferable thing to do. Everything worked well for awhile then today, out of nowhere, when cranking it up the boogie just shut itself off! I checked the fuze, which was blown. Went to the store and picked up a new one. Turned it back on, and got a faint *BZZT!* The power light turned on faintly for a second, dimmed and then nothing. Pulled the fuze out and it was blown again. I can't even turn the amp on now, for fear i'll run outta fuses! I called mesa but they're not open on Fridays because they're all such hard workers. I have a band coming in on Sunday and need this figured out QUICKLY!

Thanks!! :?

 

[pokerrules47]

do you have any spare power tubes? fried fuses can be caused by redplating tubes.

 

[playsguitars]

would faulty power tubes cause the amp to not even turn on? I think I may have a couple laying around that I'll try..

 

[fluff191]

would faulty power tubes cause the amp to not even turn on? I

Yes. If the POWER tubes arent working then the amp won't power on. And continue to blow the fuse.

 

[mikey383]

If it's blowing fuses just from flipping the power on, you probably have a rectifier tube that is bad.

Try this: Take out all the rectifier tubes and put the amp on diodes with the rectifier select switch. Replace the fuse and turn the power switch on. If it stays on, your problem was with the rectifier tubes.

Now take it out of standby. If the fuse blows now, your problem is the power tubes.

 

[playsguitars]

fuses blow no matter what I do. I tried taking the rec tube out and powering on, but it still blew the fuze. If I unpack these power tubes, I can't return them so i'm trying to get the amp to actually power ON before I take them out of the packaging. HELP ME! I think my amp is screwed!

 

[playsguitars]

OK, so i replaced the Rectifier Tube, and both Power Tubes, got the same result. BZZ and no power plus ended up with a blown fuze. Seems like this is something more serious. What's Mesa's warrenty like? I don't want to have to send this heavy thing in to them and pay for shipping, wait, blah blah. Seems like a huge hassle. Could it be the transformer is shot?

It's strange, because maybe the impedance mismatch that MESA TOLD ME WAS SAFE wasn't in fact that safe after all. They should be held accountable if that's the case. I've always gotten nothing but straight concise answers from them so far, but this time I'm second guessing them..

 

[fluff191]

You have something completely different going on man.

An impedance mismatch will be hard on tubes and wear the power tubes faster than normal, but that kind of mismatch isn't going to start taking out internal components. I have left my amp unplugged from a cab for a few minutes and didnt hurt anything, so I just have a hard time believing some kind of other condition WASNT already
at work.

Either way, its time to take it to the amp doctor man! Good luck and let us know what happens!

 

[playsguitars]

it'll be going to the doctor on monday. The repair facility is in my city, actually, so I'm so so grateful for that!
Will post up to let you all know. I just knew in the back of my mind that something was afoul when it just decided to stop working all of a sudden in the middle of a riff. My money is on the power transformer however..

 

[mikey383]

Power transformers rarely go bad, but that doesn't mean that they can't.

I don't recall for sure if a Recto has them or not, but a lot of Mesa amps have a varistor in the power supply before the PT. Those can be faulty as well.

Like Fluff said, an impedance mismatch isn't going to cause the symptoms you're seeing. In fact, what you did was the correct thing to do, so there really wasn't a mismatch.

If the amp is buzzing, you have some bad, bad stuff going on inside it.

 

[pokerrules47]

Yes, if you have replaced or worked around the rectifier tubes and replaced your power tubes, and it's still blowing fuses, it's no longer considered "user serviceable" and you are doing the right thing by bringing it into the shop.

I was very lucky when my amp was having issues as the amp tech I took it to was fantastic. He's creative and really wants to see the amps get back in the hands of the user quickly and without a return to shop trip.

Good Luck!

 

[playsguitars]

the amp was buzzing a bit but it wasn't very loud at all and i just chalked it up as normal operation. never was loud enough to cause any concern. I just hope that my warranty gets extended because of this. I'm really going to be pissed if the same thing happens down the road and it's out of warranty. That would be the pits. I've actually never ever gigged this thing. It's never left the studio and it's actually hardly ever moved! That's the discerning part about the whole thing. You would think it would be bulletproof even moreso than most boogies are. I've even heard of these amps falling off trucks and still working. mine has never even been on a car ride more than 5 miles away! haha.

So in a little while i'll post back and let you guys know what went terribly wrong.