Table of Contents
Advertisement
Troubleshooting
This chapter provides troubleshooting information for the AL1921:
1. No Screen Appear
Measured U201 pin 2 = 2.5 V?
Measured U202 pin 2= 3.3V?
Yes, all DC level exist
Disconnected the Signal cable( Loose the
Signal cable ),Is the screen show "Cable Not
No, nothing is show
Connected the Signal cable again,
Check LED status.
Led Green
Check the Wire-Harness from CN301
Check Panel-Power Circuit
Check U602 Data-output Block
Replace Power board and Check
Inverter control relative circuit
Re-do White balance adjust
Note:1.If Replace "MAIN-BOARD" ,Pleasere-do "DDC-content" programmed & "WHITE-Balance".
2. If Replace "Power Board" only, Please re-do " WHITE-Balance".
Main Board
Led Orange
OK, Keyboard no stuck
OK,Wire tight enough
OK,Panel Power OK
OK, U203 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.
Check Power switch is in Power-on
status , and check if Power switch had
been stuck ?
Measured RGB (R136,R138,R140) H,V
Input at U601 pin 4,10 ,was there have
signal ?
OK,input Normal
Measured Crystal X401(14.318MHz)
Replace U401 (MST8131B)
OK
45
Chapter 4
Led Green
Replace U601
MCU
Led orange
Check Correspondent
NG
component short/open
( Protection Diode )
and Signal cable bad ?
OK,clock
normal
Advertisement
Table of Contents
