Mark IV rack mount head.....stopped working?

[Imbue]

Hey guys,

Im new and searched a bit and couldnt find anything. I was recording last night, and the head started making a loud buzzing sound, then it lost about 1/2 its gain, and when i looked over in the corner, it was glowing red from behind the head. I went over and stuck my head behind the cab, and 1 of the 6L6 tubes was glowing red. Before i could even walk back around and turn it off, it turned itself off...LOL

I verified the fan still works, but it will not turn back on now?

Any help would be apreciated...

MG

 

[Random Hero]

Have you tried new tubes?

 

[ursinus]

Tubes and fuse. Check those first..

 

[Aart]

Probably a redplating 6l6 that blew.
The amp turned itself off because the fuse probably blew when the 6l6 died.

So check the tubes and fuse indeed.

 

[Imbue]

Thanks a bunch guys...

I called Mesa and they helped me out....They told me the same thing you guys did. They said that if it doesnt work after a fuse and tubes, then it might need to be repaird....

I got 4 new 6L6's today, they are the 440's, and it had 420's in it. (Anyone know what kind of difference to expect, if any?) This head is like 10 years old, and I have never replaced the tubes..LOL

I am going out to my studio and replace them now, i will post back the results...

Thanks again for the help,

MG

 

[Shep]

new tubes will fix it up fine..

 

[Russ]

The 420 was more of a 5881 than a 6L6.

The 440 is a 6L6.

Popular concensus is right here. Check your fuse after you replace those tubes before you power back up.

 

[Imbue]

Update:

I checked the fuse and it was toast....Replaced it with a 4A slow burn, and then replaced all 4 of the 420's w/ 440's. PLugged it in and it fired right up.

Sweet!

Holy crap though! My head used to make so much **** extra noise....LOL I mean it used to just hum and hiss all day....hehehe. I never knew until i started researching that the tubes should be replaced....LOL What an idiot...



Thanks again, and this board seems cool, i think i will go read and learn all i can!

Peace,
Miles G