IBM E50 LG CB553H Service Manual page 12

NO CHARACTER
CHECK
IC302
PIN 7 (5V) ?
YES
CHECK
IC302 PIN 1, 3, 5 ?
YES
CHECK
IC302 PIN 14, 16, 18 ?
YES
CHECK
IC303 PIN 7 (105V)
PIN 3 (12V) ?
YES
CHECK
IC303
PIN 9, 10, 11?
YES
CHECK
R, G, B CATHODE
VOLTAGE?
YES
TROUBLE IN
CRT SOCKET
2. NO CHARACTER
NO
NO
NO
NO
NO
NO
- 12 -
TROUBLE IN
P302 5V LINE
TROUBLE IN
PC SIGNAL,
P301 SIGNAL CABLE
TROUBLE IN
IC302
TROUBLE IN
P303 12V LINE/
105V LINE
TROUBLE IN IC303
TROUBLE IN
R341~R343,
L301~L303
D307~D312