My RKII won't turn on

[Tabs]

Hey guys,

Went to practice tonight and my RKII head wouldn't turn on. Checked the fuse, tried pulling/moving tubes around... still nothing.

Gonna take it in tomorrow, but wondering if anyone knows what this could be. I got it in September and aside from being left on standby for a few days back a few months ago, absolutely nothing out of the ordinary has happened to it. I called Mesa about that when it happened and they said it shouldn't have harmed a thing since there wasn't even a signal running through it.

With a tube problem it should still power on correct?

Thanks,
Ryan

 

[tele_jas]

With a tube problem it won't turn on . If a tube blows, usually that blows the fuse too. It's either a power tube (1 of the 6) or a rectifier tube.

If you get a new fuse (or 3 or 4) and put it in, switch it to solid state rectifier and then try powering it on and see if it works, if it does then it's one of your rectifier tubes.....if it blows the fuse again, it's a power tube. If it just won't turn on at all or the original fuse isn't blown it may not be a tube and may be an issue a tech would have to address.

99% of the problems with Boogies (and tube amps) are tube issues, lets hope that's all it is.

 

[ol4t]

Checked the fuse...You replaced the fuse? Sometimes it's hard to see the fuse burn. Mine wouldn't turn on, the fuse wasn't obviously burnt, it was a bad tube and the fuse was difinitely blown.
OT-Have you noticed how many Boogie problems have been the tubes? It must frustrate Mesa, they make a superior product and must rely on China and Russia for parts.

Edit- Sorry t_j, great minds think alike, you beat me to the enter button. :lol:

 

[siggy14]

from what you are saying it sounds like you are seeing absolutly no power, meaning no lights or anything. With that being said it sounds like either a blown fulse, bad power cord or bad power sorce. If you have another amp, or a computer, borrow that power cord and see if it fixes the problem.

 

[ol4t]

You know, I never looked up inside, is the power cord on the Roadster detachable? The plug-in must be hidden if it is.

 

[Tabs]

I'm taking it in here in a bit, but just to verify - the fuse won't have a break in the filament if it's blown? That's what I meant by saying I checked it - it doesn't look blown to me based on what I've seen with other fuses in the past.

How are you supposed to know which tube it is if the amp won't even turn on with a bad one? I know I've seen amps (Diezel maybe?) that will and tell you which tube it is...

 

[Platypus]

Definetly sounds like a fuse... I would replace this first before doing anything else.. check your manual for proper amperage.

http://forum.grailtone.com/viewtopic.php?t=6704

Check out this page, might help you diagnose your amp.

If that doesn't work then it's most likely a preamp tube or a power problem in the power cord.

 

[siggy14]

reach up on the inside and make sure the power cord did not come loose. Also check the fuse. If you have a DMM (multi meter) set it to ohms, put one lead on each side of the fuse, you should get a reading, if you dont then it is blown.

PS guys, as a guitarist a DMM is a very good investment, you dont have to go top of the line, you can get one at radio shack for under 20 dollars.

 

[siggy14]

A fuse can be blown without looking blown, only true way to test a fuse is with a DMM set to ohms, see my other post.

If you have no power at all, i highly doubt it is a tube. Now if you put a new fuse in and it blows again, well then it could be a tube that is causing the fuse to blow.

I'm taking it in here in a bit, but just to verify - the fuse won't have a break in the filament if it's blown? That's what I meant by saying I checked it - it doesn't look blown to me based on what I've seen with other fuses in the past.

How are you supposed to know which tube it is if the amp won't even turn on with a bad one? I know I've seen amps (Diezel maybe?) that will and tell you which tube it is...

 

[ol4t]

A fuse can be blown without looking blown, only true way to test a fuse is with a DMM set to ohms, see my other post.

If you have no power at all, i highly doubt it is a tube. Now if you put a new fuse in and it blows again, well then it could be a tube that is causing the fuse to blow.

I'm taking it in here in a bit, but just to verify - the fuse won't have a break in the filament if it's blown? That's what I meant by saying I checked it - it doesn't look blown to me based on what I've seen with other fuses in the past.

How are you supposed to know which tube it is if the amp won't even turn on with a bad one? I know I've seen amps (Diezel maybe?) that will and tell you which tube it is...

What he said. Sometimes a tube will look different. Sometimes when you put a fuse in, it will be VERY apparent which tube it is!

 

[Tabs]

Wasn't the fuse or the tubes... it's being sent in to Mesa. Will let you guys know what it was when I hear from them... this sucks.

 

[siggy14]

Did you try a different power cord? Could be that.

Wasn't the fuse or the tubes... it's being sent in to Mesa. Will let you guys know what it was when I hear from them... this sucks.

 

[Tabs]

Forgot to post what happened with this:

I got it back and apparently it was an internal fuse that blew. They said they couldn't replicate the problem and it was in working order... seems to be the case.

I'm glad it wasn't something major, but does anyone have an idea as to what could cause that fuse to blow? It literally went from working at a show just fine to not turning on at our next practice, so the problem must have occurred when I shut it down at the show or when I first tried to power it on at the practice room a week after.

My band's going on a small tour in April and I really can't afford to have this thing go dead on me like this again...

Thanks!
Ryan

 

[Troy]

I remember reading on Mesa's website a few years ago that their amps have an internal surge protection circuit.

http://www.mesaboogie.com/Product_Info/Building_Keepers/building_keepers.html

I wonder if that is what they fixed in your amp?

 

[CudBucket]

If they couldn't replicate the problem, it seems they didn't actually do anything to it. Is it possible that the internal circuit you mention can reset itself?

 

[Troy]

My assumption was that they fixed the problem, and tried to see if they could replicate what may have made that internal component go bad.

 

[CudBucket]

My assumption was that they fixed the problem, and tried to see if they could replicate what may have made that internal component go bad.

Hmmm. I don't know. The first thing they do is try to repeat the problem before they touch it.