bvtech,
Basic troubleshooting should be able to figure this out fast enough. The steps I take in situations like this are as follows, and I don't necessary perform them in any particular order; use your judgment.
Look at the base/patch cord to determine if it is damaged in any way.
Reseat the base/patch cord in both the phone and the wall plate.
Verify the pins where the base/patch cord connect are not damaged or misaligned.
Wiremap the cable
Reterminate the jack
Verify the cabling at the IDF/MDF and reterminate if necessary.
Reterminate the cross connect through MDF and IDFs on both ends if it is a digital phone.
-Swap ports to see if the problem follows the phone or the port.
Verify the strap for the PKM is seated properly.
Remove the PKM and see if the problem comes back.
-If it doesn't then the problem is with the PKM.
-If it does then the problem could be with the module or the phone.
--Swap the module out
--Swap the phone out
Trying different combinations of these steps should find the problem within a day if the problem is severe. The basic concept is to put the phone is different known good configurations to determine what the issue is. A lot of times I have seen the cabling be the issue since the heartbeat for the phone is missing or garbled. I have also seen a combination of issues as well so you may fix it so that it doesn't happen as often only to find out that there is another compounding issue; especially if there was electrical damage done.
Thanks,
TE