22
3. Troubleshooting Guide
A. LED doesn’t light.
Check Power Voltage
(TP1:3.3V, TP20:2.5V, TP2:12V)
Reference Voltage
[TP3:DVC(1.35V) and GND.]
Does “H” output in IC501
pin ?
Check and replace R705,
R706, Q701 and LED701.
Is the CLOCK Frequency of
IC501 pin 33.86MHz?
Check the power input
pattern.
Check IC501.
Check and replace
X501; 33.86MHz,
X502: 40MHz
Is the CLOCK Frequency
of IC501 pin 33.86MHz?
Check and replace IC501.
YES
OK
NG
YES
YES
NO
NO
NO
109
171
171
A-1
A-1