Sony HKDV-900, Maintenance Manual

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2-8 (E)
HKDV-900
2-3. Troubleshooting
The trouble that may occur during a self diagnostic test and its possible cause are described below.
2-3-1. Troubleshooting for the Power-on Sequence Error
All LEDs on the front panel does not light and stay the state
(1) Power supply input check
(2) Switching regulator output check
(3) Switching regulator input check
2-3. Troubleshooting
Is the cable between the power connector
(CN600) on the CP-364 board and the
switching regulator properly connected? To “(2) Switching regulator output check”
NG
Connect the cable properly and test
again
OK
Does
+
5 V DC present to the pins 1 and
2 of connector CN600 on the CP-364
board?
To “(4) CP-364 board power check”
NG
Disconnect the cable from the connector
CN600, and test the harness again
OK
To “ (3) Switching regulator input check”
NG
OK
Short between + 5 V and GND on the
CP-364 board
Does the specified AC voltage present
to the AC input terminal of the switching
regulator? Power supply line defect. Pull the cord out
and current conduction test
OK
Switching regulator defect
NG
Check the fuse on the switching
regulator
OK
Fuse defect
NG