Trouble In H.v Sync - NEC MultiSync V520 Service Manual

6. TROUBLE IN H. V SYNC
TROUBLE IN
HOR. OR VER. SYNC
YES
CHECK
CONNECTOR S702
(PIN3,4), SIGNAL
YES
CHECK
U701(PIN 40,39)
H/V SYNC.
SIGNAL
YES
CHECK
U701(PIN 32,33)
H/V SYNC.
SIGNAL
YES
CHECK
U301(PIN 3)
U402(PIN 4)
YES
TROUBLE IN
U301, U402
NO
NO
CHECK
U701(PIN 5)
NO
VOLTAGE
5V?
YES
CHECK
U701(PIN 8)
NO
FREQ.4MHz
YES
TROUBLE IN
U701
37
TROUBLE IN
SIGNAL CABLE
TROUBLE IN
H/V SYNC LINE &
Q301, Q401
NO
NO
TROUBLE IN
5V LINE
TROUBLE IN U203
12V, 77V VOLTAGE