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****! My Mesa Boogie 400+ Has Finally Failed Me! :*(

whoatherechunk

whoatherechunk

Apr 4, 2008
4,085
11
#1
I've had this thing since around the summer of 06' and it's gone strong! I've never had a problem with it! Haven't even needed to get re-tubed yet. I've always have had it ventilated and it's been in a case for most of it's life. Let's just say I've taken good care of the amp. Today I decide to take play for a little while and maybe 30 min into playing I hear some crackles and bam.....the amp completely goes out. I go to flip the standby switch and I see the sexy blue jewel light is not turned on. SOOOO yeah...the entire amp doesn't even turn on. I didn't smell anything burnt....but it doesn't even turn on. I'm hoping people like anderbass will pop in...and I know lots of other guys have had experiences with Boogie 400+'s. Does this seem like a blown fuse or a blown transformer? (s**t)! I've never had a single problem with it in the past. I'm gonna definitely take it to an amp tech but I just want to see what possible problems it could be/advice. As always, thanks a million guys.
 
#2
I would try changing the fuse before doing anything. I'd betcha there's a good chance that's all it needs.

About 5 years ago, when I got my 400+, I was so excited that when it arrived, I ran inside,
put it on my cab and turned it on to let it warm. Took some pics and finally plugged in my bass and flipped the stand-by switch on.
The thing went dead. In my excitement, I forgot to hook it up to the cab. Fortunately, it only blew a fuse. After replacing it, I used it trouble free for 4 years on the same fuse before finally trading it here for another amp.

Good luck with it.
 
#7
Keld,

Thanks a bunch! I just pulled it out and I saw some blackish-ness to the fuse. Akin to that off a burnt light bulb. Where can I get these fuses? I was thinking of calling Mesa and asking for a small batch for the future.
 
#10
if anyone has a 400+.....or well people say blown fuses are a result of a much more serious problem....can you guys elaborate on that. fuses are like a portection mechanism for more fatal problems i am assuming. I'm just wondering how i got myself into this predicament. maybe i should of been plugged into a surge protector?
 
#11
Fuses normally blow to protect the amp from over current draw. You may have had an output tube go bad, power supply cap short out, may things can cause an over current condition. Since you heard a crackle but no smoke I would not expect a blown transformer. Get it to an amp tech NOW slow blow fuses take a little time to blow, enough time to cause further damage. Do NOT just replace the fuse and try again, you will likely add to your repair bill since the failure was after 30 minutes of operation and made a strange sound before the fuse blew (fuses blowing would not make a sound, it is just like unplugging or turning the amp off).:eek:
 
#12
I disagree, you would hear a degree of fading from the amp when the fuse blows. It would fade and distort very quickly, but not instantly. The fade would be the result of the magnetic fields in the transformers and power supplies collapsing, not to mention caps discharging.
I do agree that your slow blow fuse blowing while you were playing is bad. If the fuse was getting weak, it would have let go when you turned on the amp. The sudden in rush of current pulled by the input transformer would have been sufficient to pop a bad fuse. All electrical devices pull a sudden spike of current when first energized. This is caused by the input transformers primary winding building its magnetic field. No matter how hard you play or how loud you crank it, you can not draw as much current through that fuse as when you initially turn it on. Something gave and my money is on a cap or tube. Pop the top and look at the capacitors. See if any are swollen. Capacitors look kind of like batteries soldered to the board, usually blue, black, or grey. If it was a tube, it might be discolored like the fuse. Take a look at them. They should look the same. Might be a good time to look into new ones anyways.
 
#13
Well to clarifly what I stated? If a cap shorted, or tube shorted it would drain the power supply reserves quickly......meaning no fading out. The "color" of a tube 99% of the time means nothing unless it is white (loss of vacuum). Black is a normal color on parts of a tube and a plate to cathode short can look normal from the outside of the tube.
 
#17
i'm gonna call the tech tmw thanks guys. i knowww it might be a numb nuts question....but how long do these power repairs take? what's the worst thing that i can expect? i mean i'm at a loss of words. it's like a death in the family....wellll not really...but you guys know what i mean.
 
#18
Oddly enough my 400+ is acting up as well again used it for a good 3 years so probably 5 years of use on the Harma tubes.

Turned it on, fuse popped, put another fuse in popped again so off it went to the tech, I'm expecting a call that a tube has gone finally. Quick fix and back to destroying people at gigs :D

I wouldn't worry about it one but, fuses go in all sorts of things, to me it's akin to a lightbulb going, it happensm get over it :D
 
#19
dmusic148 said:
Couldn't this result from low house voltage? Maybe he just had a local brownout.
Click to expand...

The noise preceding the fuse blowing is my concern. If the fuse just popped with no warning then low voltage or other supply problems could warrant just trying a new fuse.
Depending on how busy the shop is, time could be a couple of days to weeks? Costs under $100 to.......well you'll get a call from them. No smoke is a real good thing and IMO should give you the best chance of a repair than won't cause you to sell your car for cash? Unless you try a new fuse and let some smoke out? :help::D
 
#20
Usually, the fuse blows when a tube has gone bad.
Take a look at your tubes...does one of them look blown (all dark or all silvery maybe?).

Yes you can find the correct slo-blo fuses at Radio Shack, but it will just immediately pop again until you find the problem.
If you spot a blown tube, you can just remove the tube, put in a new fuse and keep playing the amp with 11 tubes.
 

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