Dell E176FPc, Service Manual

Page: 42 / 73

Dell E176FPc
42
9.2 Trouble shooting
9.2.1 Main Board
No display
Note:
1. If replace “
Main-Board
”, Please re-do “DDC-content” programmed & “White-Balance”.
2. If replace “
Power Board
” only, Please re-do “ White-Balance”.
Re-do White balance adjust
OK
Measured CN701 pin5/6 = 12 V?
Measured CN701 pin 9/10= 5V?
Check main board Power; is there DC level
output? Check U701 pin 2= 3.3V? U702
pin 2= 1.8V? Is there any shortage or cold
solder?
OK
Disconnected the Signal cable (Loose the
Signal cable), Is the screen show Block
WRGB color bars?
Connected the Signal cable again,
check LED status.
Green
Replace U401
Scalar IC
NG
Connected the Signal
cable again Check LED
status.
Check Power switch is in Power-on
status, and check if Power switch had
been stuck?
Orange
OK, Keyboard no stuck
Orange
Green
Check the Wire-Harness from CN101
Measured RGB (R434, R435,
R436,) H/V Input at U401 pin
89,90, Was there have signal?
Check
Correspondent
component
short/open
(Protection Diode)
NG
OK, Wire tight
enough
Check Panel-Power Circuit Block
OK, Panel Power OK
Check U401 Data-output Block
Replace
Inverter board
and Check
Inverter
control relative circuit
Measured Crystal X401
OK
Replace
U401 (GM2621)
OK
OK, U401 data OK
NG
OK