4220 static when powered on

Welcome to Audiokarma! Nice clean-up on that 4220.

Let's start to isolate where the static is coming from. Is it in both speakers, or just one? Is it affected by the volume control?

If in both channels, and is unaffected by the volume control then we'll look at the power supply.
If in one channel, we can isolate it to one side or the other of the Pre Out/Main In jacks, which will narrow down where to be looking.
 
Thanks for the speedy reply! I'll have to check on that. Come to think of it, some additional info...the right channel seems to only be about 80-90% of the left channel.
 
The level difference may just be due to the pot itself. Once in awhile I have come across some that don't track well. The best way to tell if this is the case is to use a test signal (from a signal generator, like a sine wave) fed via a "y" adapter to both channels of the Aux input at a very low level and volume pot all the way up. Measure the outputs at the preamp to see if they are even and then at the speaker jacks with a scope or DMM on AC volts. Do this with the speakers disconnected.

You could also swap the speaker wires from left channel to right to see if the speakers are imbalanced. Power off during the switchover of course!
 
I've been busy the last few days and was able to check into this last night. The static when powering on is gone. Maybe my Deoxit was not yet dry. There is still lower power on the right channel no matter which speaker I use, and it's the same with headphones and B speakers as well. The higher the volume, the worse it sounds.
 
I don't know if this is related to your problem or not, but the balance controls on the 4220 are all mounted on a circuit board with feed-thru 'griplets' connecting the two sides of the circuit board traces together. These 'griplets' loose contacts and cause balance and other issues. You can run a piece of solid wire thought the center of each griplet, bend it over and solder it to the traces on each side.

Tom
 
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