IBM ThinkVision L150, Service Manual

Page: 33 / 71

IBM 15” Service Manual
33
8.2 Trouble Shooting
8.2.1 Main Board
1.NO SCREEN APPEAR
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”
Check CN504 pin 10 = 2.5 V?
Check CN504 pin 8 = 3.3 V?
Check CN504 pin 4 = 5 V?
Check Correspondent component.
Is there any shortage or cold solder?
Check Power Board.
Yes .there have OSD show Yes, all DC level exist
Disconnected the Signal cable( Loose the
Signal cable ),Is the screen show “Cable Not
Connected” ?
Connected the Signal cable again,
Check LED status.
Led Green
Replace U202
Flash Rom
No, nothing is show
Connected the Signal cable
again, Check LED status.
Check Power switch is in Power-on
status and check if Power switch had
been stuck ?
Led Orange
OK, Keyboard no stuck
Led orange
Led Green
Check the Wire-Harness from CN501 or CN502
Measured RGB (R136,R138,R140)
H,V Input at U106 pin 4,2 ,was there
have signal ?
Measured ED101~ED108 (GM5115
only)
Check digital signal from CN101
Check Correspondent
component
short/open
( Protection Diode )
and Signal cable
bad ?
NG
OK,Wire tight enough
Check Panel-Power Circuit Block
OK ,Panel Power OK
Check U203 Data-output Block
Replace Power board and Check
Inverter control relative circuit
Re-do White balance adjust
OK, input Normal
Measured Crystal X201(14.318MHz)
OK, clock
Replace U203 (GM5115/2115)
OK
OK, U203 data OK
http://www.wjel.net