All phones don't show name or extension just one character

[gkittelson]

I handle the IT for two customers whose S8400 systems failed and the phone vendor had to replace the system boards. After they completed the work none of the phones show the extension name or number but just a strange character. These are all 4610 and 4621 phones.

Could someone tell me what to change or check in the system to make this work properly? I asked this company to fix it but they stated that they would charge more and my customers aren't interested in giving these guys any more money.