MiTAC 7521 PLUS/N Manuel D’Utilisation

112

VGA CONTROLLER FAILURE

1. Confirm LCD panel or monitor is good 

and check the cable are connected  
properly.

2. Try another known good monitor or 

LCD module.   

Display

OK?

Remove all the I/O device & cable from 
motherboard except LCD panel or extended 
monitor.

Display

OK?

Replace faulty
LCD or 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

Replace motherboard
or into board-level
Troubleshooting.

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:

U24      U2
J1          J2
Q2         Q3
Q4  

Q15

Q14       U14
SW1      R5
R7 R150
L9     

R18

R149     L537
L536     L534

Signals:

TXCLKOUT-
TXCLKOUT+
TXOUT0-
TXOUT0+
TXOUT1-
TXOUT1+
TXOUT2-
TXOUT2+

Check if 

U24, U2, J1, J2

are cold

solder?

R[2~7]301
G[2~7]301
B[2~7]301
VBHSYNC
VBVSYNC 
VBBLANK#
VGCLK
FPVCC
LID_OPEN#

FA8       FA9 
FA11     FA10
FA6       FA7
RP11     RP12
RP31     RP33
RP24     RP32
RP26     RP36
L540      R527

There is no display or picture abnormal on LCD.

YES