Sony HKDV-900, Maintenance Manual

Page: 23 / 88

2-11 (E)
HKDV-900
The display state of LEDs is no change after repeating light on and off
or the 7SEG LEDs counter display is not proper
Countdown display of the 7SEG LED is too quick or too slow
The normal (main) program becomes active
2-3. Troubleshooting
Are harnesses connected to CN400 (D-3)
and CN401 (A-3) on the CP-364 board
and CN1 (C-1 : B side) and
CN2 (A-1 : B side) on the CP-365 board
properly connected? Connect harnesses properly and recheck them
OK
Are output of IC300 (F-3), IC302 (F-3),
IC305 (F-3), IC308 (F-2), and IC310 (F-2)
on the CP-364 board proper?
NG
IC300, IC302, IC305, IC308, IC310 defect
on the CP-364 board or soldering defect
NG
OK
LED defect on the CP-365 board
or soldering defect
Is oscillating clock (12.288 MHz) of
crystal oscillator proper?
Is switch S100-1 (J-3) on the CP-364
board set to ON? Set switch S100-1 to ON and test it again
OK
Is pin 5 of CPU (IC100 (H-3) on the
CPU-364 board) low level?
NG
Switch S100 defect or soldering defect
NG
OK
Is switch S101 (J-3) on the CP-364 board
is set to the factory settings (all OFF)?
Set the S101 to the factory settings (all OFF)
and turn on the main power
NG
OK
Switch S101 defect, IC defect of
IC105 (J-2) and IC100 (H-3) on the
CP-364 board, or soldering defect