Our customer ask: " DC30 collar is no longer working. At start-up the lights remain on (they do not flash) and the GPS receiver does not hear the signal. "

I think that many owners of DC 30 and DC 40 have same issue with collar.
please do next steps:
1. Delete all dogs from your Astro 320.
2. Add dog with ID 0
3. Power on DC 30
4. select DOG with ID 0, press MENU and select "Upgrade Dog Unit"
5. DC 30 will start recovery

Attn: Don't move Astro 320 and DC 30 until update finished.

If not success, please try more attempts.