I have a customer with a MISC and a Call Pilot 150. When you try to access the system, Feature 983, Feature 981 it shows feature unavailable. I tried power cycling both the Call Pilot and phone system. I also tried XFTEST Feature 938378 and removing all of the inactive feature, then rebooting the voice mail with no luck. All four ports on the pilot are green. When I plug a phone into the extension ports feeding into the voice mail the phone comes up fine. Any other ideas?

Replace the power supply and make sure its the 8 volt version, not the old 9 volt.

Although it shows lights its not enough jam from the failing power supply.

It's common that this is the fix given that you are sure the mod cords to KSU work.

Curlycord is right - Most likely the power supply.
The old (bad) ones have 3 prongs for power.
The new ones only have 2 prongs. But they can still go bad. Replace it.

Also note: You said that all 4 lights come on. (left side)
You did not say anything about the second light from the top on the right hand side. If that light does not come on, you are not working.

Installed new power supply and everything came back up fine. Thanks for the help, you guys are great!