Batboard

I don't have the radio in my hands but a friend of mine has a CDM1250 he bought that will not power up. It has a constant low level hiss when you have it plugged in to the power supply. My first thought was the radio was programmed for ignition control ,so he plugged up the ignition to pin 10. Still no power up and has the low level hiss. That reminds me of an HT750 when it has an EEPROM CS ERROR . No error on the display,any ideas ?

what's the exact model number? is it a 750 with a 1250 head on it?

HMMM, I did not think about that. I never ask him what the full model # was.