Troubleshooting For Nv-Ram Test Error; Troubleshooting For Led Test Error - Sony HKDV-900 Maintenance Manual

2-3. Troubleshooting

2-3-6. Troubleshooting for NV-RAM Test Error

An error is displayed
Is the connection between pin 119 of
IC200 (G-1), pin 6 of IC201 (G-1) and pin 6
of IC203 (F-1) on the CP-364 board proper?
OK
Is the connection between pin 120 of IC200,
pin 5 of IC201 and pin 5 of IC203 proper?
OK
Are R220 (G-1: B side), pin 5 of IC201,
pin 5 of IC203 on the CP-364 board set to
+5 V? (Measure when an error indication
appears.)
OK
IC defect of either IC200, IC201 or IC203

2-3-7. Troubleshooting for LED Test Error

Only one LED does not light or it is dark
Are output signals (ON : +3 V to +4 V/
OFF : GND) of control ICs (IC300 (F-3),
IC302 (F-3), IC305 (F-3), IC308 (F-2), and
IC310 (F-2) on the CP-364 board) proper?
OK
Is cathode to LED properly connected to
GND?
OK
Is control signal (anode ON : +2 V/OFF :
GND) to LED proper?
OK
LED that does not light is defective
2-14 (E)
NG
Connection defect between IC200, IC201
and IC203
NG
Connection defect between IC200, IC201
and IC203
NG
Parts defect of R220 or soldering defect
NG
IC defect or soldering defect
NG
Resistor defect or soldering defect
HKDV-900