Trouble Shooting - Lenovo SPECTRUM Series Service Manual

6. Trouble Shooting

6-1.MAIN BOARD
1.NO SCREEN APPEAR
Check CN504 pin 10 = 2.5 V?
Check CN504 pin 8 = 3.3 V?
Check CN504 pin 4 = 5 V?
Measured CN402 pin 1/2 = 5V?
Yes, all DC level exist
Disconnected the Signal cable( Loose the
Signal cable ),Is the screen show "Cable Not
Connected" ?
No, nothing is show
Connected the Signal cable
again, Check LED status.
Led Green
Check the Wire-Harness from CN4 or CN5
was tight enough?,
check the Wire connection to panel side too
Check Panel-Power Circuit Block
Check U4 Data-output Block
Replace Power board and Check
Inverter control relative circuit
Re-do White balance adjust
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"
Led Orange
Check Power switch is in Power-on
status and check if Power switch had
been stuck ?
OK, Keyboard no stuck
OK, Wire tight enough
OK ,Panel Power OK
OK, U4 data OK
Check Correspondent component.
Is there any shortage or cold solder?
Check Power Board.
Yes .there have OSD show
Connected the Signal cable again,
Check LED status.
Measured RGB (R15,R17,R24) H,V
Input at U3 pin 4,2 ,was there have
signal ?
Check digital signal from CN1
Measured Crystal X1(14.318MHz)
Replace U4 (MST8011B)
OK
14
Led orange
Check Correspondent
component short/open
( Protection Diode )
and Signal cable
bad ?
OK, input Normal
OK, clock
normal
Led Green
Replace U6
Flash Rom
NG