IBM 9493-AW1 Service Manual page 17

4. NO RASTER (OSD IS DISPLAYED) – AD9884
NO RASTER
(OSD IS DISPLAYED)
YES
U5
POWER PIN
3.3V?
YES
CHECK
R,G,B INPUT?
U5 PIN 7, 15, 22
YES
CHECK
IIC PULSE ?
U5 PIN 29, 30
YES
CHECK
CKREF(H-SYNC) INPUT?
U5 PIN40
YES
CHECK
COAST INPUT?
U5 PIN41?
YES
CHECK
CLAMP INPUT(H-SYNC)?
U5 PIN28
YES
CHECK
CLOCK INPUT
?
(25MHz-95MHz SINEWAVE)
U5 PIN115
NO
NO
NO
NO
NO
NO
NO
- 17 -
CHECK U19, U20,
U23, +3.3V
1. CHECK PC
2. CHECK SIGNAL CABLE
& D-SUB CONNECTOR
LINE
CHECK IIC LINE
CHECK H-SYNC LINE
(D-SUB→U11→U18
PIN40)
CHECK CKREF INPUT
CHECK SIGNAL LINE
FROM U14 PIN17
TO U5 PIN28
CHECK SIGNAL LINE
FROM U5 PIN115
TO U1 PIN254
(1024x768/85Hz : 95MHz)