McIntosh (MC601) amplifier overheating problem

It also should not cost $400 to replace each transistor that is ridiculous and an indication to all that the service center is not what it may appear to your friend to be. 

Ok, now I remember why I quit posting here years ago.  

I am an electrical engineer.  I read the repair order.  I design amplifiers.  The issue is bad output transistors.  They have repaired it twice by replacing them twice.  But there are like 4 dozen transistors in each amp.  Chuck Hinton recommended the service center to me.  Now can you please go away.  Thank you.

If $400 is the total price and not per transistor, then that is not unreasonable.  $400 per transistor is stupid.  

However, if the tech tested the unit, took it apart and found only one failed output transistor, understand that he/she had to test each one on the side (right or left) that failed, replace it, put the unit back together, test it, package it then yes, $400 isn’t unreasonable. 

Say you you have a stereo amp with push/pull outputs and one side failed.  Most new amps have protection circuitry so the entire amp shuts off and I don’t know which side had the problem.  So I have to disconnect each side separately from the power supply to see which works and which doesn’t.  Now that I know which failed.  There are a few ways to test transistors in circuit.  Non are as accurate as removing each one, testing it and replace the bad ones.  I also have to test the pre drivers because an output driver failing sometimes fails pre drivers. 

My point is that is a lot of work and testing.  If the end result is only one transistor failed (unlikely), it still was a lot of work. Say 2-3 hours labor and if the amp was constructed like a mark Levinson 23.5, then it’s more. Very hard to take apart and remove transistors.  $400 not unreasonable 

I started by saying it was unreasonable and then thought it through.