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. WTF

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?