This is an odd one for me. This client has been working flawlessly for MANY years. Now when you come off hook there is a scratchy noise over the dial tone for about 1-2 seconds then everything sounds fine.

The KSU has one station expansion card and this happens on all phones all lines.... ....INCLUDING the intercom.

If this was dirty contacts I would have expected it to be on a single line or at least limited to a single bank of 8 stations. I would prefer not to replace the KSU but it seems to be pointing right at it.

Anybody seen this one?

Could be the PSU

Yes, I've seen this exact thing recently. I couldn't find any easy fix, so the customer has just learned to live with it. I agree that it is likely a power supply issue, which is one of the only components in Panasonic systems that seems to fail consistently, regardless of the product.

Thanks Guys!

I suspected that as well. I'll see if I have one to swap before a new cabinet.