KR-4200 - Is this a DC offset issue?

[@udi0$lave]

I also don't see where to adjust this on the board. View media item 15751
Happens after it warms up for a while.

 

[@udi0$lave]

Only does this on the right side

 

[petehall347]

yes unplug it . looks like its gone negative at the output . thats if the speaker is wired correctly .

 

[@udi0$lave]

How difficult a fix is this on the 4200?

 

[petehall347]

no idea sorry .

 

[hopjohn]

Looks like a major offset issue. Disconnect your speakers. Place all the controls to neutral, volume to minimum, set the receiver to speakers A, mode to AUX with no components connected. Measure the DC voltage across the right + and - A speaker terminals with a digital multimeter. Be sure not to short the terminals with the multimeter leads by insulating all but the tips. Report the voltage here and then we can discuss further.

 

[mikepick]

This thread has a lot of info:

http://audiokarma.org/forums/index.php?threads/kenwood-kr-4200-repair-notes.628534/

According to page 2, looks like DC offset is not adjustable, you would need to replace and gain match Q1-4 on the main power board. Could be those are failing... if you have a meter, the thread has a number of voltages you can test to see where there might be anomalies, before and after warm-up.

Edit: I'll defer to @hopjohn, do as they suggest first!

 

[rickl]

Wow Mike. Nice thread link. I haven't read it all but good job hopjohn.

This should be enough for audioslave to get his little 4200 working.