Mesa Rev F Repair Woes

  • Thread starter Thread starter TotallyRadGuitars
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TotallyRadGuitars

TotallyRadGuitars

Well-known member
Hello all. Back at the start of May, I jumped on a local swap shop who had gotten an early, chrome chassis Mesa Dual Rectifier Rev F - with the early "Mark III" transformers too!
So it sounds great in the shop, but I'm not playing it loud or for very long, I know I want it. So I get it home, and start rocking out, only to have all of the LED's fade out and sound goes away. A few minutes later, pops right back on no problem. Sometimes, I'll get half an hour, other times only 10 minutes before issues, and if you smack the amp on the top physically it pops back on sometimes. Ok, clearly we have something wrong, loose solder joint or etc.

So I open her up, and I find this absolute mess around R232 and R233, looks like those two resistors must've blown up, melted the cap casing next to it, and burned out a trace on the PCB too. Someone tried to repair this... poorly... by tacking on some random tall resistors (wrong values) and covering the burned trace with a small piece of metal soldered in at both ends. Botched repair job sure, but it doesn't seem insurmountable to someone with more expertise - so I decided this was one for the repair shop and not for me.

Here's a few pictures of what the trouble spot looked like:
bYE1CQR.jpg

uDEbN0B.jpg


Anyway, it's been over 2 months now, called multiple times just checking for the status and last I heard on 7/11 was that the amp hasn't even made it to the bench yet. That's not great but I get it, people are busy, it's summer, whatever. I'm really not a high pressure guy. But, I hear back directly from someone at Mesa today. Apparently, they do not have the PCB scans for any early 2-channel rectifiers, and the repair shop tried to do some kind of repair to the PCB and it ended up being non-conductive so the amp still doesn't work. I'll add some pictures of that once I get the amp back and see what they tried to do.

So a few questions. I only see one trace that is damaged. Is it really so difficult to replace that one line, and swap the two resistors to the correct value? Maybe I'm way underestimating this repair but I've watched a lot of videos online using that trace repair "pen" and other methods that make drawing a single trace line look... pretty simple? Maybe I'm just not getting it, so please someone tell me if I'm way off base here.

And my next question, ultimately they are saying this amp has to go back to Mesa Boogie for a factory repair. I am a little worried that they might replace the PCB entirely with a new one or something, which would be a hell of a kicker on the value of this amp, being Rev F and all that. Has anyone had something vintage and/or relatively rare go back to Mesa for repair? Do they respect the integrity/design of the original circuit, or will they do some unwanted updates? I'm probably worried about nothing, but what was a fair deal on a Rev F is quickly becoming the most expensive Mesa I've ever bought. I guess I'm a little frustrated (not directed at any one person in particular, maybe the original owner who did this repair) and trying to make sure the rest of the process as smooth and inexpensive as possible.

I'll have the amp back in hand tomorrow. Talking with Mesa later to schedule a possible repair. I'll update with more info as it goes.
 
ikes man :(
good luck
not a tech
hope it is not a PCB full replacement, but it sure looks like it is headed for that
 
Man, I definitely would have approached the swap shop for a partial refund. Especially if they were asking for Rev F pricing of a good to go amp.
 
I think Dave Friedman has a guy that works with him who formerly worked at mesa, might be worth a call. I think it could be demolested but it’s gonna require a board pull with a fair bit bit of fixes.
 
where do you live? If anywhere near Atlanta there's a guy here I would trust with an older Mesa. Jon Bailey
 
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not sure how skilled you are at this, but i think you should just tear that thing down to the chassis, and take the board out.
You'll be able to see all damaged traces that way, and you should be able to just desolder all that stuff, clean it up, replace the components, fix the traces, and put it back together. I'd test all the ldr's, recap it, up any 400v caps to 630v, clean all the pots and jacks, while you're in there.
Its a mesa, it'll never die. You can probably do this, it just might take a while, and not be fun.
If you don't have the time, or would rather pay someone else, just bite the bullet and send it to mesa. it'll cost like $150 more onto your repair for round trip shipping, but they'll get it done right and they won't ghost you or jerk you around.
 
skoora said:
Man, I definitely would have approached the swap shop for a partial refund. Especially if they were asking for Rev F pricing of a good to go amp.
Click to expand...
I did speak with the owner and he seemed amicable to something, but we didn't put anything in writing. Now this repair place has had my amp for over 60 days so I'm far past any kind of "official" return policy but I guess I kept expecting it would work out. I'm going to try to be trusting - I've bought a lot of stuff from that swap shop and he's always been fair with me in the past so I am still optimistic it'll work out ok, even if he just cuts me a deal on some other thing I buy there later. I was waiting until I had a receipt for the repair total so I could go back and say "Hey, that repair cost me $X, help me out and give me $X off of this item I want."

skoora said:
where do you live? If anywhere near Atlanta there's a guy here I would trust with an older Mesa. John Bailey
Click to expand...
I'm in Orlando FL. I appreciate the recommendation but I already got RMA #'s from Mesa. Mesa actually reached out and called me directly, I guess they've been working with the guy at my local shop already and when he decided to throw in the towel, they took the initiative to contact me. Actually pretty cool of them especially in the modern world where that kind of stuff is not common (even if they stand to make a few hundred bucks from me for it).

JimAnsell said:
not sure how skilled you are at this, but i think you should just tear that thing down to the chassis, and take the board out.
You'll be able to see all damaged traces that way, and you should be able to just desolder all that stuff, clean it up, replace the components, fix the traces, and put it back together. I'd test all the ldr's, recap it, up any 400v caps to 630v, clean all the pots and jacks, while you're in there.
Its a mesa, it'll never die. You can probably do this, it just might take a while, and not be fun.
If you don't have the time, or would rather pay someone else, just bite the bullet and send it to mesa. it'll cost like $150 more onto your repair for round trip shipping, but they'll get it done right and they won't ghost you or jerk you around.
Click to expand...
I seriously considered this but I'm just gonna send it off to Mesa and get it done proper. If it was a less special amp I'd have a go at it but for something as cool as a Rev F I just want it done the proper way and I'll try to get some of the bill covered by the shop that sold me the amp.

"They'll get it done right and won't ghost you or jerk you around."
100% agree there. Maybe it'll end up being a Christmas present to myself (by the time it gets fixed) :ROFLMAO:
 
TotallyRadGuitars said:
Hello all. Back at the start of May, I jumped on a local swap shop who had gotten an early, chrome chassis Mesa Dual Rectifier Rev F - with the early "Mark III" transformers too!
So it sounds great in the shop, but I'm not playing it loud or for very long, I know I want it. So I get it home, and start rocking out, only to have all of the LED's fade out and sound goes away. A few minutes later, pops right back on no problem. Sometimes, I'll get half an hour, other times only 10 minutes before issues, and if you smack the amp on the top physically it pops back on sometimes. Ok, clearly we have something wrong, loose solder joint or etc.

So I open her up, and I find this absolute mess around R232 and R233, looks like those two resistors must've blown up, melted the cap casing next to it, and burned out a trace on the PCB too. Someone tried to repair this... poorly... by tacking on some random tall resistors (wrong values) and covering the burned trace with a small piece of metal soldered in at both ends. Botched repair job sure, but it doesn't seem insurmountable to someone with more expertise - so I decided this was one for the repair shop and not for me.

Here's a few pictures of what the trouble spot looked like:
View attachment 226375
View attachment 226381

Anyway, it's been over 2 months now, called multiple times just checking for the status and last I heard on 7/11 was that the amp hasn't even made it to the bench yet. That's not great but I get it, people are busy, it's summer, whatever. I'm really not a high pressure guy. But, I hear back directly from someone at Mesa today. Apparently, they do not have the PCB scans for any early 2-channel rectifiers, and the repair shop tried to do some kind of repair to the PCB and it ended up being non-conductive so the amp still doesn't work. I'll add some pictures of that once I get the amp back and see what they tried to do.

So a few questions. I only see one trace that is damaged. Is it really so difficult to replace that one line, and swap the two resistors to the correct value? Maybe I'm way underestimating this repair but I've watched a lot of videos online using that trace repair "pen" and other methods that make drawing a single trace line look... pretty simple? Maybe I'm just not getting it, so please someone tell me if I'm way off base here.

And my next question, ultimately they are saying this amp has to go back to Mesa Boogie for a factory repair. I am a little worried that they might replace the PCB entirely with a new one or something, which would be a hell of a kicker on the value of this amp, being Rev F and all that. Has anyone had something vintage and/or relatively rare go back to Mesa for repair? Do they respect the integrity/design of the original circuit, or will they do some unwanted updates? I'm probably worried about nothing, but what was a fair deal on a Rev F is quickly becoming the most expensive Mesa I've ever bought. I guess I'm a little frustrated (not directed at any one person in particular, maybe the original owner who did this repair) and trying to make sure the rest of the process as smooth and inexpensive as possible.

I'll have the amp back in hand tomorrow. Talking with Mesa later to schedule a possible repair. I'll update with more info as it goes.
Click to expand...
I've sent multiple amps back to mesa for TLC and potential (not invasive repair) and mods. Mike B will likely speak with you directly about it and I always tell them to not change anything on the revision (unless it is a mod) and they respect that. I tell it to the person doing the RMA to note and tell Mike directly.
 
Just make sure you let them know you don’t go for all this high brow, elitist vintage nonsense and they should make it G spec for that classic ‘98 sound…lol
 
The only way to fix that is to carve out the burnt sections of the circuit board and re-route any affects circuit paths. The burnt board creates a carbon path for short circuits. No repair for it but to remove it. or replace the board.
 
Send it to mesa, that's probably the best option and they are really reasonable with their repair cost.
 
Mesa could repair it but they definitely don’t have any spare boards for the Rev Fs! Hope you made out ok!
 
peterc52 said:
Does anyone have the schematic for a rev f?
Click to expand...

I can't take credit for, some very dedicated people on the boogie forums I believe created this one. Based on the Rev G schematic and then manually "de-falsified" by putting in the correct values and paths for Rev F.

https://totallyradguitars.com/s/Dual-Rectifier-Solo-Head-2ch-RevF-De-Falsified.pdf

---

To update this thread, I just sent it off to Mesa for repair. They said it could be potentially months before I see it again, but I'll update once I have it back.
 
I'd imagine there's some way to 'jump' over the burned traces and bypass those areas; pretty labor intense though and as Jerry P said, that burned area needs to be addressed. Hopefully that original board can be saved in some fashion. If if has to be replaced, then it's not a Rev F anymore. Unfortunately.
Good luck!
 
I always understood that you can clean the burnt areas well and then seal them with shellac or another material that prevents conduction?
 
Looks like some crack head got in there with a dirty 100w soldering iron.

It can be fixed by someone who knows what they're doing. I would agree with having MESA take it as others have stated.
 
This is my biggest fear with used gear. Lately I've been buying a ton and have run into a lot of issues but nothing like this. Hope you get it worked out.
 
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