ViewSonic P774B-2NT Series, Service Manual

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18
6-6 ABNORMAL VERTICAL SCANNING
1. ABNORMAL VERTICAL SIZE
OK
NG
OK
NG
READJUST V-SIZE FUNCTION VALUE
RELATIVE CIRCUIT
CHECK VERT. OSC CIRCUIT
RELATIVE CIRCUIT
NG
READJUST V-SIZE FUNCTION VALUE
CHECK THE VOLTAGE OF IC101
RELATIVE CIRCUIT
CHECK IC401 PIN 20, 21, 22, 23
CHECK THE IC601 PIN 2 ABOUT 11.8V
PIN 4 ABOUT -12V
CHECK D601, C605
2. VERTICAL CENTER
NG
READJUST V-CENTER
RELATIVE CKT
CHECK IC401 AND IC601
6-7 SIDE-PIN CUSHION DISTORTION
NG
READJUST SIDEPIN
CHECK IC401, Q404, Q405, Q406
RELATIVE CKT.
6-8 POOR FOCUS
READJUST FOCUS CONTROL
NG
CHECK FOCUS CONTROL UNIT,
FOCUS LEAD WIRE, CRT SOCKET & CRT