I just put in a refurb'd Partner system into a small motel. Not sure which rev. It's been in about a month and now I'm getting complaints of room phones ringing all night for no apparent reason. When they answer the call they hear static. Any ideas?

Sounds like you got a bad card or cards.

Perhaps shorted I/W on one extension, causing it to dial another extension?

If you have a DSS, or all the extensions mapped to buttons on a phone, maybe you can see extensions off hook when it happens

Are these phones per chance the the old MLS phones.?

I would assume they are single line sets.

Thanks for the ideas. All phones are s/l's. What I did was ran a backup of the programming, defaulted system (which I should have done to begin with) and uploaded the programming. That was Monday. Today is Friday and I haven't heard back. My fingers are crossed.