My SC-901 radio with 3CD changer was occasionally acting up whereby it would not load and play CD's. The last three times this happened all I did was remove the radio completely, disconnecting everything (NEED YOUR RADIO CODE!) and plug it all back in, turn it on, enter the code and all is well. Disconnecting the battery did not have the same effect. Still had to enter the code but the CD still didn't work. I have no clue whatsoever what's going on here but this procedure has worked for me three times. No, the CD didn't just go south by itself, there were mitigating circumstances involving me fooling around with power, the alarm system, console removal etc etc. Try this first if your SC goes south.