Service manual

5 Troubleshooting
5-2 SyncMaster 770TFT
5-2 No Video
Check signal cable and connection.
Check IC201 and related cirmit.
Does the input signal appear at Pin of 76, 77, 78,
80 of IC601 (LDTGB, LVSYNCB, LHSYNCB, LCKBB)
Yes
No
No
Does the analog video signal appear at R211,
R212, R215? (BLUE, GREEN, RED)
(IC201)
Yes
Check IC201, IC206 and related
circuit.
Does the sync signal appear
at the output of Pin 14 of IC201and Pin 3 of IC 206 ?
(V-SYNC, H
*
V SYNC)
Yes
No
Check the related circuit for these
ports
No
Check IC501 and related circuit.
No
Check IC501 and related circuit.
No
Check IC 300 and related circuit.
No
Does the input signal appear at the Pins 40, 41
of IC 300?
( PLL H
*
V, MX
-
PDEN)
Yes
During power on-off, does the input signal
appear at the Pin 29,30 of IC300?
(AD
-
SDA, AD
-
SCL)
Do the clok and sync signal appear at Pin 115,
117 of IC 300? (DCLKAB, MX_HSYNC) and
does the digital video signal appear at thr output
port PDA, PDB)?
Yes
During power on-off dose the input signal
appear at the R 407 and R 408 ?
(MX
-
SDA, MX
-
SCL)
Yes
7 8
9 10
1 2 3 4
5 6
Does the digital video signal appear
at the Pin 34, 35, 39, 40, 42, 43, 45 and 46 of IC601?
Yes
Is the output of Pin 1, 17 of IC501 High?
Check TFT-LCD panel and Inverter.
Yes
Check IC601 and related circuit
No
15 16 17 18
Check IC501 and related circuit.
No