Burned Yamaha B-6

I must say that it is not too bad to repair the B-6 for such a compact amplifier, I had a Classè repaired last month but that was a lot of work with all boards above each other.
 
The two B-6's in my signature were picked up off of the bay as "parts/repair" . Each one had a burned up channel.
Here is the debris field of one of them.
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and the other..

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I may have maybe $300 tied up in the two.
 
Yes I know, i scrubbed with sandpaper and cleaned it 5 times with an oven cleaner, there is no residue left, just soot.
The print is good to go.

There was also a lot of the burnt capacitor on the main board, and this has also been cleaned with oven cleaner.
halve of the board is charcoal
 
Around the same time, I picked up a third one.It had a power supply issue. Its still sitting on my awaiting repair shelve in pieces. I cannibalized output transistors and emitter resistors from it to repair the other two.
 
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The two B-6's in my signature were picked up off of the bay as "parts/repair" . Each one had a burned up channel.
Here is the debris field of one of them.
index.php



and the other..

index.php


I may have maybe $300 tied up in the two.

Well, the first one is indeed a lot, the second is half that bad. It can not be seen as a malady, but perhaps misuse or abuse of the amplifier, which caused him to break.
I have also repaired some M-60 amplifiers and I noticed that the same channel was always defective and the "auto class a" was burned.
 
Likely shorted speaker wires or lack of ventilation.

Yes indeed, I was recently with someone who had a set of quad's and that was also connected with 5 cm of stripped speaker cord which could cause a short circuit in a small movement, I said something about it and the man really had no idea.
 
I have also repaired some M-60 amplifiers and I noticed that the same channel was always defective and the "auto class a" was burned.
I have repaired M-60's,65's,80's and 85's that were similar in the number of components destroyed when the amplifiers "Chernobyl'd".
 
I never fail to be amazed by the knowledge of folks who understand electronics and how they work, no disrespect to all who contribute, but avionic in particular. He speaks of components as if they are almost human. This attempt to repair the B6 and get the Phoenix to fly again is impressive. Best wishes with the project. I am keen to put my toe in the water but I am just too busy as a full time worker. I also think I am a little to theoretical and analytical (due to current work mode of over 30 years) and lack the hand eye co-ordination to do the soldering etc. Maybe I should give it a go when I stop my current job and need to fill in empty hours - hope my brain will still be up to it. Its nothing short of fascinating to me. Keep going gentlemen its great to follow the posts and responses
 
For me it is a thing to relax and repair some nice yamaha amplifiers (and some other brands), for my work I adapt many control cabinets of butane and propane installations to current safety requirements, but my interest lies more in electronics.

I have already made a new loudspeaker terminal to modernize B6.

I am still waiting for the X2 capacitors from England, post sometimes takes a very long time.
 

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What type of material did you use for the base? I've been using garolite.
 
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