I bought a Beocom1 system with three handsets. One hour after registering all three the system failed inasmuch as there was no dialtone. After checking everything, I disconnected the power to the base , waited two seconds, reconnected and registered one of the handsets. The dialtone returned but only for 5-10 minutes. This happened many times.

Then I read, on this forum, how to reset the handset with 9#9#9*HOLD. I then re-registered that one handset and voila! I've had a dialtone for about  one hour. The other two handsets are fine.

I reset the other handsets. After about 2 hours the problem re-ocurred. There is no dial tone. The only way to get a dial tone is to disconnect the base for two seconds and re-register the handsets. 

Defective base?

This sounds very strange, I have never heard this before(I'm sure some of the other BeoWorlders have).

I guess that you have testet it on another signal output?

If that doesn't help I would take it back to the dealer, and get a new setup.

Software update should help.

This indeed sounds very strange.. so just to understand you correct - When you press the hook key you get no dial tone? This raises a lot of questions in order to investigate your problem:

1. Was there any error messages in the display?
2. What if you (while you expect the dial tone) try using a different (corded) phone?
2a. Do you then get a dial tone in that phone?
2b. And does that give you a dial tone in the Beocom 1 handset?
3. What does the other handsets write in the display when you wait for dial tone in the first handset?

Br,
Burnix