Harman Kardon hk 490i

rathern0tsay

New Member
Hello all,

Just having registered, and new to this forum, I have bought a hk 490i from the local GW and am having issues with it. The right channel is very low (has no bass response whatsoever), and distorted, while the right channel is mostly normal, unless the bass knob is in the flat position (middle), then it cuts out completely. If I turn it a little to the left, the left channel comes in normally, albeit a little distorted. I have a DMM and some electronics experience. Anyone have a clue? Thanks in advance!
 
I've had a 330i, 570i, and 690i, and they all have been nightmares. The fusable resistors love to go out for no reason (or sometimes good reasons), there's corrosive glue, and the blue colored caps leak electrolytic. Check resistors and do a recap, make sure bias is ok as well as power supply voltages.
They sound great when working, but it's tough to get them going again sometimes.
 
Did you read the thread on using deoxit? In my experiences, 9 times out of 10, deoxit fixes these type of issues. Maybe you didn’t spray enough? Also, do all the controls. Especially the tape monitor switch. Sometimes the issue is a combination of dirt. I’ve had some that I deoxited with a generic brand, and it didn’t fix it. Gave them to my tech, and he used the real thing, which fixed it. Don’t give up yet.
 
I recently brought back a 330C from the dead with simple cleaning all switches and pots. This would be my first thing to do.

Once you know everything is clean, you can focus on any remaining issues.
 
Thanks! I am ordering some deoxit, but used electronic contact cleaner. Its a weird situation for that receiver. Once I cleaned all the controls, when I turn the bass to the center detent, there is no left channel sound, if I turn it to the left a bit, sound comes in but then quickly fades, even if I don't move the control anymore. Strangely possessed I think :)
 
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