Sony STR-DN1060, Service Manual

Page: 29 / 158

STR-DN860/DN1060
29
SECTION 5
TROUBLESHOOTING
Flow of Repair (when sound is not outputted) (1/5)
NG
NG
START
Check that the “PROTECT” is not displayed on the fluorescent indicator tube.
NG
NG
OK
NG NG NG
OK
OK
OK
OK OK
NG OK
OK
OK
Check that voltage of the following pin is 3.3 V. MB-1409 board: IC3002 pin 76 (PROTECTOR) Check that the defect is not improved, even if you do the following works. 1. Short - circuit the both ends of the
C3011 on the
MB-1409
board.
2. Perform the “SHIPMENT MODE”
(refer to pa
ge 20 on t
he original
service
manual).
Check the IC3002 on the
MB-1409
board and the surrounding circuit, and exchange the defective parts. Check the surrounding circuit of power transistor (example: Q1600 on the MAIN board) and the surrounding circuit of power amplifier circuit (example: FL on the MAIN board), and exchange the defective parts.
– Continued on page 30 –
Check that the following fuses are not damaged. MAIN board: F910, F911 STANDBY board: F901 Check that the power transistor (example: Q1600 on the MAIN board), the power amplifier and the surrounding circuit are not defect. Check that the surrounding circuit of current detect (example: Q1600 and Q1601 on the MAIN board) is not defect. Check the surrounding circuit of protector (example: Q1604 on the MAIN board), and exchange the defective parts.
Check that between the +59 V line/–59 V (±B) line and the ground does not short circuit. Check the surrounding circuit of power transistor (example: Q1600 on the MAIN board) and the surrounding circuit of power amplifier IC (example: PWR AMP on the MAIN board), and exchange the defective parts. Check the surrounding circuit, and exchange the defective parts. Measure the power transistor (example: Q1600 on the MAIN board) with a tester, and check the following things. 1. Check that the circuit does not short-circuit. 2. Check that resistance is normal.
Check the surrounding circuit, and exchange the defective parts.
Measure the power amplifier circuit (example: FL on the MAIN board) with a tester, and check the following things. 1. Check that between the power supply
line and the ground does not
short-circuit. 2. Check that resistance is normal.