My cabinet died

[Koreth]

Exactly what it says on the tin.

Friday night, during rehearsal, everything with my rig is working fine. The pedals work, the cables all work, the amp works, everything is good. Saturday we pack up our gear at the rehearsal space and head to the show. Nothing went wrong during loading and unloading, nothing was dropped or jostled around violently or anything.

During sound check once I had everything connected I took the amp out of standby and strum a few chords. Nothing. Okay, weird. Maybe one or both pedals are having issues, let's bypass those and go just straight Guitar -> Cable -> Amp. Still nothing. Okay, let's try the other cable. Still nothing. Um...what? Is the cabinet plugged in? Yes. Is my guitar's volume turned down. No. Is the amp's volume turned turned down. Ahha! Yes it is, 'cause the sound man had asked me to turn way down as our amps could easily overtake his PA and make it hard for him to mix properly.

Okay, strum a few chords and still nothing. ******, did the knobs on my amp get banged in again when it got carried inside? (The Mesa/Boogie Nomad's most common problem.) Check each knob and each channel and still nothing.

At this point, most of the rest of the band is set up and ready to go, and I'm triple and quadruple checking that everything is connected correctly. Now the sound man and the rest of the band are waiting on me. The sound man didn't seem to be in the mood to deal with busted gear, and so told me to borrow the amp from one of the other guitarists playing that night. One of the guitarists let me borrow his speaker cord and his amp and still nothing. Finally we managed to get sound out of the amp when I plugged my amp into his cabinet.

Yay! Sound! At this point we're probably 10 or so minutes over on time, so the sound guy checks my levels real quick then has us start.

I am quite grateful that my amp did not take damage and fry its output transformer or the output tubes when it was working into an unknown (but probably open or shorted load) while I was troubleshooting and trying to figure out what the heck was going on. Another point for the toughness of Mesa/Boogie.

So, now I have a dead cabinet. How do I go about fixing this thing?

 

[Virtual Kevorkian]

Re: My cabinet died

Luckily, not much can get busted in a cab unless you somehow managed to knock the magnet/voice coil off of every speaker. Open it up and check all the wiring, as that's surely your problem.

 

[woemoejack]

Re: My cabinet died

yes, definitely a wiring issue. what kind of cab is it?

 

[Koreth]

Re: My cabinet died

Peavey XXL 4x12 slant. From the gossips I've seen around on the Internets, I get the impression that it isn't Peavey's highest quality or best sounding cabinet. To be fair, it is made from low density particle board. But it has been a good cabinet to me thus far, and I'm frankly surprised at the trouble last night.

Frustratingly, it doesn't look like the cabinet opens up. There's no screws or bolts or anything for the back panel - it is all tolex all around. This means it is a front-loaded cabinet, doesn't it? I am going to have to remove the front grille and baffle to get to the speakers, aren't I?

 

[CTN]

Re: My cabinet died

yep.

take the speaker baffle out, and that should show you all the wiring for the cab. If I were you, I'd get some good speaker wire and redo the whole cab, just to be safe.

 

[krankguitarist]

Re: My cabinet died

Yeah, as others have said, you likely have a wiring issue.

Easy fix with the most basic of soldering skills. Hell, if they use slip-on connectors (which is a definite possibility, considering that the thing isn't working) you might not even need that.

Check the plate where you plug into your cabinet. The problem is likely there.

 

[woemoejack]

Re: My cabinet died

the input would be the best place to start troubleshooting, since all of the speakers were dead, this is the more than likely your single point of failure.

 

[Koreth]

Re: My cabinet died

Thinking about this, I realized that last night, I was running the borrowed speaker cabinet out of one of the 4Ω jacks, as the cabinet was an 8Ω cabinet and that's the correct load when running the amp at half-power. My Peavey cab is 16Ω, and I run it out of the 8Ω jack, as 1) the amp doesn't have a 16Ω jack and 2) that's the correct load for half-power. However, the 8Ω jack was recently replaced by a repair shop after the original one was destroyed when the amp took a spill off the cabinet. Thinking that maybe the repair job was botched and I simply had a bad jack, I decided to test this out.

No such luck. When hooking my 8Ω 1x10 up the the 8 ohm jack, I get no sound out of the amp. When I hook it up to the 4Ω jack, I get sound. While that would support the bad jack theory, when I hook my 4x12 up, I get no sound regardless of which output jack is used.

So now I have not only a dead cabinet, but a dead output jack as well. I'm really hoping it's just a bad jack, and that I didn't fry the output transformer in such a way as to kill the 8Ω tap or secondary. Jacks are cheap and can be replaced fairly easily. No so with transformers.

 

[WhoFan]

Re: My cabinet died

strange stuff... reminds me of an issue i have with Marshall which i'll start another thread on.... but i use lots of Peavey amps and cabs, and i find their stuff is good quality even in the cheaper end... whatever the true issue is with your set up i'd be carefull... you do not want to blow your tube head's transformer with running it on mis-matched loads and or cabs with bad wiring... i'd say get the whole rig to a tech...

 

[Koreth]

Re: My cabinet died

I checked again, the 8Ω jack is fine. I didn't have the speaker cord plugged in all the way. So that's twice now I've dodged the bullet of not killing the output transformer by running the amp into an open load, however momentarily. So the amp has been set to the side before I do kill it.

I can't figure out how to get the front of the speaker cabinet off. The front panel with the grille cloth is shifts around when I sick a screwdriver in the seams, but I bent my screwdriver trying to pry the front panel away from the speaker baffle. I think I need to find my crowbar.

I was able to peek inside the guts of the cabinet by taking one of the handles off. and pointing a flashlight inside. Sure enough, it's a wiring issue. There's a blue wire with a female spade terminal hanging loose in the cabinet, and there's an open male spade terminal on the speaker jack. Now all I have to do is get the damn grille off...

 

[GoldenVulture]

Re: My cabinet died

I checked again, the 8Ω jack is fine. I didn't have the speaker cord plugged in all the way. So that's twice now I've dodged the bullet of not killing the output transformer by running the amp into an open load, however momentarily. So the amp has been set to the side before I do kill it.

I can't figure out how to get the front of the speaker cabinet off. The front panel with the grille cloth is shifts around when I sick a screwdriver in the seams, but I bent my screwdriver trying to pry the front panel away from the speaker baffle. I think I need to find my crowbar.

I was able to peek inside the guts of the cabinet by taking one of the handles off. and pointing a flashlight inside. Sure enough, it's a wiring issue. There's a blue wire with a female spade terminal hanging loose in the cabinet, and there's an open male spade terminal on the speaker jack. Now all I have to do is get the damn grille off...

Boxes I've come across with a sealed back , you usually have to get into them by removing the speakers.
I found this

new XXL 4-12 cab. slant with casters. loaded with blue marvel 144 speakers. why 16ohms? wished it was 8. the cab is sealed. i planned to replace the speakers with celestion greenbacks but i see no way to get inside. the speakers appear to be loaded from the rear and then sealed shut. ????

I couldn't find a clear pic of the cab any where.You need to get the grill cloth out some how.
You shouldn't need to force anything too hard..

 

[WhoFan]

Re: My cabinet died

not sure if it's the same as my 5150 cab but i don't think all speaker cloth grills come out without wrecking them.. i believe they are meant to stay put on some cabs and you can only access the speakers from the rear

 

[Koreth]

Re: My cabinet died

the grill clothe was on a separate panel that is held to the front of the speaker baffle with apparently some super strong Velcro that would probably be perfect for pedal boards. It took a crowbar and some elbow grease, but I got it off. Took a speaker out of the hole, reached in and connected all the wiring back together. Now everything works again. Yay!

Getting that grille off was a PITA though. I think the next cabinet I get will be a rear-loaded one.

 

[GoldenVulture]

Re: My cabinet died

the grill clothe was on a separate panel that is held to the front of the speaker baffle with apparently some super strong Velcro that would probably be perfect for pedal boards. It took a crowbar and some elbow grease, but I got it off. Took a speaker out of the hole, reached in and connected all the wiring back together. Now everything works again. Yay!

Getting that grille off was a PITA though. I think the next cabinet I get will be a rear-loaded one.

:bigthumb: I was wondering if it was a velcro setup.That must've been annoying.
Good to see it's happening again.