Document Title
SV42LMUB_AX_US_HSM
Page No.
42 / 92
Document No.
LF100-000210
Revision
1.0
The information contained in this document is the exclusive property of HannStar Display Corporation. It shall not be
disclosed, distributed or reproduced in whole or in part without written permission of HannStar Display Corporation.
6. Troubleshooting Flow Chart
6.1 No Display
Power Board
Fail
Check F3
+5V
IR/Key pad
Fail
U67 circuit Fail
Check
U1
Is Led
Blue/light back?
U1 circuit
Fail
Check DDR
U2,U3
U2,U3
circuit Fail
END
No Display
NO
NO
YES
YES
NO
YES
YES
YES
NO
NO
Check
U67 +3.3V
Check
U21 +1.2V
U21 Fail circuit
C
3.3V Flash
IC
NO
YES
D71 ,Flash
U20,U76
circuit Fail
NO
YES
YES
Check
Rest/X1
Reset/
X1
signal Fail
NO
YES
Check
IR/Key pad
NO
BL-EN circuit
Fail
Is CON38
PIN1 high?
NO
YES
YES
Q24,Q3,Q2
2andQ2
circuit Fail
Check
Q22 +5V,
Q2 +12v
NO
YES
C3.3V,
U4+1.8V,U25+1.
2V,U46+1.2
V
U51,U4,
U25,U46
circuit
NO
Check
PANEL
PANEL
Fail