Back of amp flashes with a blue light when turning amp on

[Nickocaster]

When I just turned on my Mark V, the back of the amp lit up shortly with a blue light. A flash of light against the back of the wall. It happened a few weeks ago as well. Amp sounds great, no problems when I play it. I have played it for hours since the first flash. No weird smells, smoke or any other sonic difference. I changed all the tubes mid July. Anyone knows what this might be?

 

[Eevil]

Some power tubes flash when they’re powering up I’ve thought it’s normal..

 

[Nickocaster]

Thanks for answering. As long as nothing bad is going on, I can live with it.

 

[Nickocaster]

Anyone from Boogie have an idea what it might be? Is it harmful?

 

[jaslan]

If you want an official answer from Boogie, just call or email them. They have been really responsive when I have contacted them.

 

[Nickocaster]

Thanks for the tip! I just got of the phone with a tech and I’m going to bring it to him. I’m located in The Netherlands so sending it to Mesa is going to be a little expensive I think.

 

[mace]

This happened to me multiple times. Each time it was a bad rectifier tube doing the flashing. Replace and all is well. I would say it is not normal for the flash which can be seen against the wall. Boogie told me that back when I had my issue. So, try to find that flashing tube and replace it, I would say.

 

[Nickocaster]

Thanks Mace! Finally someone who had the same experience. Yesterday I turned my amp on and no flash. I’ll check the tubes to see which one it faulty. I have an idea the Jan/Philips 12at7wa in V4 might be a candidate. I changed the rectifier tube in February, so it might be dying by now.

 

[mace]

I’d be surprised if it was one of the 12ax7s or 12at7 or whatever since those are canned. But you never know! I would think it would be one of the power tubes or rectifier tubes since those are not covered up.

 

[Nickocaster]

That’s what I was thinking as well. I have a feeling it’s the rectifier. It hasn’t happened since and I have played it several times. Unfortunately for some weird reason the rectifier tube isn’t available anymore here in The Netherlands. So haven’t been able to get one yet.