Common problem?

[Varkatzas]

I am a touring musician, and our bass player ran into some problems a few weeks ago and I need some help. He bought a Mesa M9 Carbine straight from Mesa about 3 months ago, put it in his 8 Space rack and we've been using it about 30 minutes a day since. At a show the other day, his head started just randomly cutting in and out. Like it will work for about 15 seconds, then cut out for a few seconds, then come back in.

We have tried different basses, cables, cabs, and it still does it. We used to have an SVT4 that did this same thing for awhile, and ended up breaking altogether (because of the fan blowing hot air on the sides in a rack). The M9 shouldn't have this same problem should it?

Could it be a simple fix like a fuse for the reason it is doing this? We need to send the head back to Mesa to get it fixed but not sure if it will be worth the shipping cost if it is just a small little problem

thanks guys

 

[JimmyM]

try pulling it out of the rack and see if it does the same thing.

 

[hdracer]

I would pull it out of the rack and put a small fan on it to see if it is a over heating problem. If it still does it then you have eliminated that.

 

[B-string]

Agree with removing from the rack and trying again, very well could be heat build up from poor airflow.

 

[Rick Auricchio]

A fuse either works 100% of the time 0% of the time. There's no in-between.

 

[bass4worship]

The amp is going into protection so check out the speaker cable or cab('s)

 

[Varkatzas]

Sorry for late bump-

I took it out of the rack and tried it on a cab for about 5 minutes and it seemed to be working fine. I will do a more in depth check tomorrow, but whats the deal with rackmounted heads not working in a rack? This is the second I have had not work in a rack (first was svt4)

right now i have it in a 6 space rack, power conditiioner and tuner on the top, and the m9 on the bottom spaces. i can't tour without the head being in a rack, so should i raise it up a couple spaces so it has air underneath it as well?

 

[Bass_Pounder]

Rack fans are your friend

 

[Varkatzas]

Rack fans are your friend

Would you suggest a rack fan to blow air in the rack or out of the rack?

 

[M0ses]

Would you suggest a rack fan to blow air in the rack or out of the rack?

That depends on your rack equipment. Each one will absolutely require to have a specific way, and if you have it the other way, you can pretty much guarantee an overheat eventually.

 

[Bass_Pounder]

That depends on your rack equipment. Each one will absolutely require to have a specific way, and if you have it the other way, you can pretty much guarantee an overheat eventually.

Exactly.

You need to establish which direction your amps are venting heat.

My amp vents rear to front, so my rack fan blows cool air into the rear.

If your amp vents to the rear or to the sides, you need to have the fans blowing out the rear to suck the hot air out of the rack.

 

[lighthouse]

When you tried different cabs, etc., were you still at the venue? Maybe it was a problem with the venue power.

 

[B-string]

Be sure if it vents out the side you have at min. 3/4" on each side of the amp head or install vents on the side of the rack.

 

[totallybacan]

B-String, I hate to change the subject, but does the fusion blow front to back or back to front?

 

[Varkatzas]

When you tried different cabs, etc., were you still at the venue? Maybe it was a problem with the venue power.

We tried at several different venues

We have the M9 Carbine and I know the fan is in the back but not sure which direct it blows, i'll try and check tomorrow

 

[countrybassist]

It sounds like his rack isn't allowing for enough air flow. I had an swr sm 500 that did the same thing. I attached an external fan to my rack to blow on the head. I never had that problem with that head again.

 

[B-string]

B-String, I hate to change the subject, but does the fusion blow front to back or back to front?

Sucks in from the back and blows out the front.

 

[BassmanPaul]

Then racking the unit should cause no problems as long as the back of the rack is open to cool air and not blocked by a curtain or other stuff thrown on top of the rack.

Paul

 

[unlined4string]

A few other things you could check for would be an itermittant short circuit in the speaker cable or speaker cabinet internal wiring, or dirty contacts on the effects loop jacks (check for this by running a known good cable in the effects loop).

 

[Varkatzas]

does anyone know what kind of fan i should get for the Mesa M9 Carbine? I know the fan is in the back but not sure if it blows out or in and I have no cab to test it and dont want to turn the head on with no load