Mate, I am using Nokia media master 8830s for 4 years now, and I have encountered the same problem that you have. But I have already fix the problem in mine. Maybe this one will help you.
1. open the cover of your receiver.
2. Look for the 47uf 400v capacitor across the diode of the main power
supply. Check this capacitor for leakage or open. Or better replace this