2270 right amp board

They occasionally show up on the auction site. It’s buyer beware there. Is yours unrepairable?
 
Sure would like to see one of AK’s Marantz experts look at it. Someone with loads of experience with that specific board might be able to fix it. Where are you located?
 
There is an incredibly detailed paper here on AK by Ecluser on bias on the 2270 and I have used it to get bias control by adding small value resistors in R784 and R785 if I remember correctly, bias transistor replacement and or bias potentiometer. Its not usually much beyond that if the output transistors are not leaky etc. If the traces are good and no toasted components I have only had to replace diodes or emitter resistors in extreme circumstances. The emitter resistors (those big white 0.2 ohm jobs) are not really able to be checked statically to determine their functionality in the circuit. I have been at the point of just wanting to buy a working board many times and have always been able to find and repair the culprit(s) .
 
You can't use MJE150** for drivers in some 2270 amp boards .
They don't play well with the circuitry.
Maybe that's what the other techs were using.

Bob
 
I would suggest giving Bob (wlhd1610 above) a PM. He is near you and a serious expert. He just finished a Marantz 1200 integrated amp for me that was in very bad shape electronically. He is very experienced with Marantz Receivers and amps.
 
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