MiTAC 8050QMA - Manual (Page 118)

117
80 80 50QMA 50QMA N/B Maintenance N/B Maintenance
8.4 External Monitor No Display-1
There is no display or picture abnormal on CRT monitor, but it is OK for LCD.
Yes
Re-soldering.
No
One of the following parts on the mother-board may be
defective, use an oscilloscope to check the following signal or
replace the parts one at a time and test after each replacement.
Parts:
U710
U2
J702
J723
L11
L2
L10
L30
Signals:
+3VS
CRT_DDDA
CRT_HSYNC
CRT_VSYNC
CRT_DDCK
CRT_RED
CRT_GREEN
CRG_BLUE
Check if
J702
are cold solder?
Display
OK?
External Monitor No Display
1. Confirm monitor is good and check
the cable are connected properly.
2. Try another known good monitor.
Remove all the I/O device & cable from
motherboard except monitor.
Display
OK?
Replace faulty monitor.
Connect the I/O device & cable
to the M/B one at a time to find
out which part is causing the
problem.
Yes
No
Yes
No
Board-level
Troubleshooting
Replace
Motherboard
MiTac Secret
Confidential Document