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Mesa Boogie M-2000 Basis bias setting etc.

#22
Hi Guys. sorry for interrupting. I've just got my hands on broken M Basis amp. it's one big unknown for me at this stage. One tech will try to fix it for me. I've opened the casis to see what the story inside was.

Please tell me what that bit is for and if there is anything mossing here on the circuit board in Power supply section.

Thanks for help.

Cheers.
Marcin
15566481226181382628936781620897.jpg
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#23
Somebody got into your amp and damaged the PCB from improper soldering and handling. This needs to see a qualified service tech, a Mesa authorized service center would be best. There's no telling what other damage may have been done.
 
#25
Marcin Plato said:
Thx Agedhorse. Do you own this amp? could you post pic and description what is missing? cheers
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I work for Mesa. The damage to the PCB is obvious in your photo. Because of this, the amp needs to be gone over with a "fine tooth comb" to see what else has been screwed with.

Where are you located?
 
#27
Nobody is going to give you "hints", there are obvious problems on the primary side of the power supply and that's dangerous. Because there's no way to know what else might have been screwed with, EVERYTHING needs to be inspected by somebody familiar with that amp, and anything wrong needs to be corrected. I am assuming that this still still has the factory power transformer and wasn't modified in an unapproved manner?

I am not in the position to help you with this. It's a job for the authorized service agent in your country, for safety reasons as much as anything else. Otherwise, you are on your own.
 
#28
I appreciate your point of view and I understand that you want Mesa amp to be serviced in Mesa's service.
I know that good electronic head can fix it.
Mesa is no different than any other amp.
Iy hac circuit boards, condensers, resisyors etc

Do You see any logic in thesis:
Good Year tyres can only be changed by Good Year service partner? Nonsense!

I'm looking for picture of that part of PCB guys. I hope there is at least one persan that can help me out. Thanks.
 
#29
Marcin Plato said:
I appreciate your point of view and I understand that you want Mesa amp to be serviced in Mesa's service.
I know that good electronic head can fix it.
Mesa is no different than any other amp.
Iy hac circuit boards, condensers, resisyors etc

Do You see any logic in thesis:
Good Year tyres can only be changed by Good Year service partner? Nonsense!

I'm looking for picture of that part of PCB guys. I hope there is at least one persan that can help me out. Thanks.
Click to expand...
You are not understanding what I am saying, so I'll try it again in a more simplified way...

Because your amp has been hacked on and I see obvious things that are wrong, there's no way to know how much additional damage has been done (throughout the amp) except by inspection from somebody familiar with the specific details of your amp.

Sure there are similarities between amps, but there are also major differences. The differences are very significant as there are some unique aspects in your amp that are unlikely to be recognized by a technician not familiar with (read as experienced with) your amp model.
 
#30
You're right I don't understand your enigmatic explanation.

On the other hand you don't understand that there are people that are not Mesa employees with ability to fix Mesa amps.
It looks like you think all non Mesa tech's are idiots not able to read schematics. I'm not fluent in fixing amps but available schematics don't show any elements that are out of this world. Every circuit and single element can be checked step by step.

Good luck. I'll keep looking for real help.
 
#31
Marcin Plato said:
You're right I don't understand your enigmatic explanation.

On the other hand you don't understand that there are people that are not Mesa employees with ability to fix Mesa amps.
It looks like you think all non Mesa tech's are idiots not able to read schematics. I'm not fluent in fixing amps but available schematics don't show any elements that are out of this world. Every circuit and single element can be checked step by step.

Good luck. I'll keep looking for real help.
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And you still don't understand, because you simply can't understand.

It has nothing to do with non-Mesa techs being idiots. It has to do with the tech knowing what it's SUPPOSED to look like so they can recognize what may have been changed. There are very few of these amps out there, and in many of these cases where a hack tech made a mess of an amp we have to break out the engineering benchmark unit so that we can visually compare point to point. This is time consuming, but necessary whenever a product has been changed from how it was originally built. Since the problems I see are on the primary side of the circuit, these require additional scrutiny for product safety reasons. It's not necessarily about being able to read schematics, nor how good (or bad) an tech might be, but the additional resources required whenever a product has been changed from how it was originally built. I'm somewhat familiar with your amp, I would not be comfortable working on what I see without being able to go back to the build diagrams and the benchmark unit. There are too many places where errors can hide.

Does this help?
 
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#35
Hey! The problem is, because Mesa changed this amp many times, and the schematics are not the same for every M2000 model. I owned 3 of those amps, two early models (which I still have), and one late (final year) and they are all different inside (many small differences, but also different boards added etc.), and also all very different sounding. The best sounding (and the loudest) is still the one from the first year of production. Here's a photo of my power section:
DSC05233.JPG
 
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#36
Marcin Plato said:
I have picture I was looking for from decent forum user.

One advice for You. Stop telling people what they do or don't understand Mr Smart guy.
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Ever hear of the term "you can't understand what you don't know"?

That's what you are up against. Disrespect doesn't improve your odds.
 
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#38
Abouth that orange capacitor (or whatever it is) on the photo… My early M2000 model was blowing a fuse quite frequently (when turning the amp on), and this orange capacitor was added by (supposedly) official Mesa tech in Italy (Esse Music provided this)… but the problem wasn't solved. Later, when my local tech took a look inside, he removed this orange thing… he said there's absolutely no logic for this to be in there… and he added a thermistor for soft start next to the fuse. Problem solved!
 
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#39
Marcin Plato said:
Have a good day!
Click to expand...

If you would have had more time on this site you would recognise the the gentleman you are insulting is one of the most helpful, knowledgable people on this site. He has given you the best advice possible. As an employee of Mesa he obliged to follow the procedures set out by the company to cover such events as yours. Your amp has been modified/repaired/screwed up by someone with insufficient knowledge to do the work. Your amp needs to be seen by someone very familiar with the amplifier to ensure that it is safe for you to use. This is for YOUR benefit and you should realise this and not shoot the messenger!
 
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#40
Dear BassmanPaul

1. I haven't insulted anyone. I replied using same words as "the gentleman".

2. I was looking for the picture of same section of this amp. That's all. If I wanted to get it fixed by Mesa Tech I would know where to find them.

3. Any tech fluent in electronics can fix any amp. Specialistic equipment used to diagnose each section/element + knowledge base is enough. That's a fact.

4. I got this amp broken and I was aware of possible problems that's why I was looking for help coming from forum users. Advice to go to Mesa service is no advice to me. I have diagrams for this amp which is enough to check each section step by step by qualified tech - any tech fluent in electronics.

5. Forum is open for discussion and sharing experiences if anyone has problem with different point of view shouldn't engage in conversation.

7. To close that discussion. There is socket missing on the PCB thats why wires going from transfomer are connected direct. And that is fine. If Mesa tech would want to help he would simply say that someone got rid of the socket but You can connect cables direct.

Regards
 

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