Welp, my brand new Mark IV is broken.

[psychodave]

Just like the title says.

I fired it up and the volume was almost non existant. I could crank it on 10 and it was TV volume. So I changed all of the preamp tubes. Sure enough it fixed it... and revealed a static noise in it that comes and goes as it pleases on every channel. I have literally tried everything to make it go away. I have tried 2 sets of known good power tubes, 3 sets of known good preamp tubes and the noise wont go away. I tried checking every jack, cables (even thought the noise is there with or without a cord plugged in). Different speaker cables, different cabinets etc. I tried wiggling all of the preamp tubes to determine if it is a dirty socket, but nope. The static occurs on either tweed power or full power. Now I have to go through the hassle of sending it back. The funny thing is that after 20+ years of playing, this is my FIRST new amp I have ever purchased :doh: . I guess I should stick to used.

I would like to mention that through the static, this amp is BRIGHT. Jesus Christ, it is so bright that I while using the "classic" V eq, I had to adjust the 6600 to flat.

 

[JimAnsell]

its brand new from mesa, or a store or what?

i went though 2 roadsters that had problems brand new.
the first one i fixed, the second one i couldn't figure it out.
i got a brand new mark IV from guitar center a few days ago that was a floor model at another store.
that worried, me, but it showed up clean, and a 2 2 hour band practices, and at least 3 hours of home play, i haven't found a problem yet.

did you call mesa at all?
are any of the pots scratchy at all?
did you take the chassis out, fire it up, and poke at componets with a pencil when it got staticy?
thats how i located the 2 bad pots that make my other mark 4 noisy.

 

[psychodave]

its brand new from mesa, or a store or what?

i went though 2 roadsters that had problems brand new.
the first one i fixed, the second one i couldn't figure it out.
i got a brand new mark IV from guitar center a few days ago that was a floor model at another store.
that worried, me, but it showed up clean, and a 2 2 hour band practices, and at least 3 hours of home play, i haven't found a problem yet.

did you call mesa at all?
are any of the pots scratchy at all?
did you take the chassis out, fire it up, and poke at componets with a pencil when it got staticy?
thats how i located the 2 bad pots that make my other mark 4 noisy.

Brand new from a store...in CO (I am in PA). I just got it today and tonight was the first time testing it out.

Couldnt call Mesa...they are closed on Friday.
No pots are scratchy.
Did not take the chassis apart...and I dont think I will.

 

[JOEY B.]

Brand new from a store...in CO (I am in PA). I just got it today and tonight was the first time testing it out.

Couldnt call Mesa...they are closed on Friday.
No pots are scratchy.
Did not take the chassis apart...and I dont think I will.

Other than tubes, I would not touch it. I hope MESA will cover any shipping costs, if they occur. This sounds like the day that I am having, not amp related, thank goodness.

 

[eltrain858]

have you tried turning the reverb all the way off?

 

[fatoni]

no solution but i thought id mention that i would kill for a mark iv that could be cranked and only be at tv volume

 

[MesaDCLP]

i would kill for a mark iv that could be cranked and only be at tv volume

+1

or for that matter, any mesa!!!

As for the problem ... Go for the warranty instead of wasting your energy!!!

 

[Random Hero]

I like 6600 about flat, and even below it

 

[Dr. Tweedbucket]

That's a bummer. Did you confirm that the bad tube is in fact a bad tube? Maybe that one preamp tube socket is hosed up and not making optimum contact.

If that's not it, and you put all known good tubes in it, sounds like maybe a cold solder joint? :?:

Yep, I wouldn't tear anything apart, Boogie is good about standing behind their products.

 

[MusicManJP6]

It seems that used amps seem to work like they should because the bugs have all been sorted out after the first year or so... I've not had an ounce of trouble with any of the Mesas i've owned! They have all been used. Two Mark IVs (one A and one B - both were early to mid '90s models), my Roadster head, and now an F-30 combo. Once they get past the initial break-in and debugging stage, they seem to be rock solid...

Good luck with the outcome. It would be hard to have a shiny new amp that doesn't work right!!

 

[jvk]

Just like the title says.

I fired it up and the volume was almost non existant. I could crank it on 10 and it was TV volume. So I changed all of the preamp tubes. Sure enough it fixed it... and revealed a static noise in it that comes and goes as it pleases on every channel. I have literally tried everything to make it go away. I have tried 2 sets of known good power tubes, 3 sets of known good preamp tubes and the noise wont go away. I tried checking every jack, cables (even thought the noise is there with or without a cord plugged in). Different speaker cables, different cabinets etc. I tried wiggling all of the preamp tubes to determine if it is a dirty socket, but nope. The static occurs on either tweed power or full power. Now I have to go through the hassle of sending it back. The funny thing is that after 20+ years of playing, this is my FIRST new amp I have ever purchased :doh: . I guess I should stick to used.

I would like to mention that through the static, this amp is BRIGHT. Jesus Christ, it is so bright that I while using the "classic" V eq, I had to adjust the 6600 to flat.

My advice is not to switch it on anymore as you're risking more damage and more blown tubes and send it back for repair, I would actually push for replacement if it's new. By the sounds of it, you could have several things wrong with your amp, if a preamp tube fails catastrophically, the connections inside it can get fused and the anode/cathode can come in contact, which means a few hundred volts will dissipate accross it's plate resistor and/or cathode components. In plain language, there are quite probably some toasted resistors inside your amp that need replacing.

Do any of the tubes your replaced look a little milky compared to the other ones?

 

[Elpelotero]

have you hit the ground switch?