Mesa Boogie Mark 2B Issue

[bluespwr101]

Hi to all. Newbe here.
I have a late '70's, early "80's mark 2B. Non verb, no EQ. 60 watts. All stock, no mods.
Just had to factory for a complete cap job, replaced a couple of pots ect...
Got the amp back Tues 7-26-11.
Didn't have time to try it that evening.
Next morn., (not even in my posession 24 hrs) Went to fire 'er up. All was fine and worked as should untill I had been playing it for @ 1-1&1/2 hrs. Then the amp got staticy, and lost power.
Sounds like @ 1/2 - to 1/4 power. All new tubes -pre, and power.
Went to try it again this morn., and all was fine... untill it again got hot.
Called Rich at Mesa-Stumped!
Amp is mint. I am original owner.
Has Altec 4178H spk. 8 ohms in amp which was stock spk when purchased.
Tried am w/diffetent spk., same power loss and static.
Also tried different amp head w/stock spk., NO PROBLEM w/spk.
I've been playing pro over 38 yrs. Am 56 yrs old and have played 'em all!
Both guitars, amd amps.
Any one else dealing/dealt with this issue? Anybody got a fix?
Frustrated, tired, and stumped. And right about now, brain dead.
Thanks,
Dennis James -( for all you googlers out there.) :?:

 

[McBarry]

Welcome Dennis,
mega info,experience,knowledge and good friendships to be had here - enjoy!
A couple of ideas:
- try tapping on tubes gently in case a socket is loose.
- take signal from preamp out - does that signal fade too? - U might have done this with the "different amp head w/stock spk"
- equally, inject a signal to power-amp in - does that signal fail?
- any chance the fuse is old and starting to fail - agreed bizzare, but plausible and super easy fix.
- is it before the amp - pedal batteries, cables,pedalboard etc etc
Are you handy inside the chassis - look for burnt tracks/board/parts to start. WITH amp off.
Dry joints fit your description, but it really could be a ton of things..
Dave

 

[zodiac272]

hey,
welcome!

sorry about your amp, it should be great after service from mesa factory. i would suggest calling and talk to mike bendinelli. He worked on your amp, and knows more about it than anyone else. He will get it taken care of

scott

 

[bluespwr101]

Thanks to all who have posted. I spoke to Rich-(head of tech dept. yesterday) and she is going back for a return visit and real good going over since only the obvious was adderssed. Leaving on Mon.
********************************************************************
Posted today- 7-29-11 2:55pm East coast time
I kind of left some of the conversation I had w/Rich out here, beacuse I needed to process what he had told me. The more I thought about it, the more it pissed me off! What Rich told me, and I quote," We WILL be charging you for a new repair, and issueing you a new RA number." Basically what I got out of this, is that Mesa was not going to stand behind the work they just performed, and to me, not even back in my posession for 24hrs and kaput! All I sent them was the chassie /tubes when I sent it originally. I am quite sure the amp was not maintained at operating temp for 1-1+1/2 hrs as I stated on the repair order. I can be pretty sure that it was repaired in an open air/air conditioned enviroment, and not put into a combo setting like where it resides and can build up heat. I sure hope they make this right. It was supposedly a total rebuild. I have a bag full of old parts to back this up, along with the work order. I own 4 Mesa amps total, and maybe not for much longer.
1. Blue Angel
2. F - 30
3. 5:25 express head and 1 x 12 wide body cab
4. Mark 2B Boogie.
(There's a few Marshalls, Fenders, and Dr. Z's in the mix also.) - but not up for sale.
If they don't make this right, these are all going on e-bay.
Example - Mesa did a complete cap job. I tested all the caps when I got them back, and there wasn't anything wrong with any of them. No leakage of any sorts. No buldging or swelling. They were all holding the correct voltage and values. Yet I was charged for this. Did the amp really need this, - In my opinion NO!
As a professional player, I will not recommend them to any other players, or ever purchase another one of their products. Being a pro, I have long arms with quite a reach if ya know what I mean. I come into contact with alot of players on the road. Word of mouth goes a long way. Especially if it comes from me. They all know I speak nothing but the truth. Rock On!
Thanks, and all please take this under advisement.
Dennis :x
**********************************************************************
UPDATE 7-29-11 5:03pm East Coast Time
Just got a call from mike bendinelli at Mesa. He personally has reassured me that this issue will be dealt with at NO CHARGE to me, and they are standing behind their previous work. (Glad to here that one!) Also stated Mesa will do what ever it takes to get the amp playing, and make it right.
Every one please excuse my above rant, common sense does still prevail! Guess it's who you know.
Sincerely,
Dennis

 

[McBarry]

Dennis, I get your "vent", esp to hear they WILL charge for new work..
Although if it's clearly a NEW fault and simply ***** luck in the timing, I think payment is reasonable, although proving same would be a drama..
Re caps, 2 distinct schools of thought exist, and Mike B has changed his position over the years it seems..
Sounds like you recieved the "preventative maintenance" theory ie; change them now before they break in future, but equally some guys have posted their's WEREN'T changed as they were within spec..
And someone from Mesa was posting, saying they used "lifetime" caps... so it really is a minefield.
I take notice of the learned tech's here, who seem to replace 20+ yr old caps before they fail.. makes sense to me..
.02 worth..
BTW, can't wait to hear what the problem was/is,
Dave

 

[bluespwr101]

Dave,
Thanks for the feed back (LOL)!
I spoke w/Mike directly yesterday, and he had relayed to me exactly what had been done/not done to my amp. Your "preventative maintenance" theory was exactly correct.
Will keep all posted. Have a great w/e. (F. Y. I. might be 3-4 weeks before any news)
Sincerely,
Dennis

 

[boogiemon]

Mike & Rich are two different people w/two different jobs. Rich sets expectations but Mike is very fair & stands behind his work. Don't stress too much till the deal is done.

 

[Restless Rocks]

In the last couple years It's become alarming at how many BRAND NEW name brand tubes I've installed that failed either immediatly or within a few hours of being powered up. It makes one think that they are not tested at all under operating voltages. Please be patient with Mesa and staff. They are well known for having the best product support and customer service in the business.

 

[bluespwr101]

Patience my friends, is one thing that I myself have an over abundance of. Mesa has been great to me, in all of my yrs. doing business w/them.
Yesterday, I decided to take the bull by the horns, as they say.
I removed the chassie from the cab., and inverted it upon 2 pieces of 2 x 4's.
I then removed all the pre-amp tube shields, leaving all the tubes exposed.
I had the amp playing for @ 1hr. & 15mins. At that time I was debateing weather to send it back or not. It was not exhibiting any issues at all.
Then, (no sooner then that thought leaving my feble little mind,) she started to act up.
So..... I started to wiggle all the tubes, one by one. When I got to the power tube next to the phase inverter and wiggled it, the amp came back to life at full power.
Every time after that when the amp faded to power loss, I wiggled that same tube, and wahlah...magic happened once again. I couldn't see any loose connections at, or on the mother board. My eyes aren't what they used to be, but my ears are just fine. But there is definately some involvement with that power tube, and whatever else is tied into that circuit.
Hopefully I was able to point Mike in the right direction. Time will tell. So off she went to the factory today. Will keep all posted. Lets all keep our fingers crossed for my little buddy.
Sincerely,
Dennis :idea:

 

[bluespwr101]

Hi to all. Chassie returned to me on Mon. All is well in Boogie Land. Kudos to Mike and Mesa.
Please excuse my frustrated rants. That's all that they were-I think we all know that. So....my apolligies to any and all if I offended you in any way. This was not my intention. The problem was a bad power cap between the phase inverter and power tube #1 causing the driver tube/socket to short. If I hadn't started wiggeling stuff around, it may have never been found, and probably was there from day 1, according to Mike. He said this was a wierd one. But He's the MAN! MY BOOGIE"S BACK!!!!!
Rock on!
Dennis

 

[McBarry]

Good stuff Dennis!
Sounds like a 0.1uf coupling cap between the PI and power tubes?
But how was it shorting?
Whatever the specifics, good it's back in circulation,bringing good tones/toons to the masses.. Noice!
DB