Pioneer VSX-816-K Service Manual - Page 134

1 2 7.3.4.3 Troubleshooting Step 1: Connectors A CN701, CN702 Are the connectors securely inserted ? Yes To STEP 2 No Insert the connectors securely. Step 2: Power supply B 1 CN702 (pin 4) 5 V input Is No the voltage 5 V ? Yes Is there any loose No connection of CN702? Yes Check the MOTHER Assy. 2 C IC703 (pin 3) To STEP 1 3.3 V Regulator IC input Is the voltage 5 V ? No Check the patterns in the path. Yes 3 IC951 (pin 14) 3-5 Converter D 4 Is the voltage 5 V ? No Check the parts and patterns in the path. Yes IC771 (pin 5) USB Power SW Is the voltage 5 V ? No Check the parts and patterns in the path. Yes E 5 IC7814 (pins 14, 15) DAC Is the voltage 5 V ? Yes No Check the parts and patterns in the path. 3 4 6 IC703 (pin 1), IC702 (pin 7) 3.3 V Reg. output / 1.8 V Reg. input Is the voltage No 3.3 V ? Yes Is IC703 abnormally hot? Yes No Replace IC703. The output and GND may be short-circuited. Check the path between them. 7 IC762 (pins 37, 47) FLASH ROM Is the voltage 3.3 V ? Yes No Check the parts and patterns in the path. 8 IC761 (pins 1,3,9,14,27,43,49) SDRAM Is the voltage 3.3 V ? Yes No Check the parts and patterns in the path. 9 IC953 (pin 14) 5-3 Converter Is the voltage 3.3 V ? Yes No Check the parts and patterns in the path. 10 IC701 (pins 16,33,64,76,112) USB Media control IC Is the voltage 3.3 V ? Yes No Check the parts and patterns in the path. 11 IC702 (pin 1) 1.8 V Regulator output Is the voltage 1.8 V ? Yes No Is IC702 No abnormally hot? Yes Replace IC702. The output and GND may be short-circuited. Check the path between them. A F 134 VSX-816-K 1 2 3 4