LG TL-AT130M - Manual (Page 12)

3-2
SECTION3 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE
1. Power Circuit(SMPS)
(1) No 5.3 A (2) No 9V
Is R101 normal?
YES
NO
NO
NO
NO
YES
YES
Is there Vcc (about 13~19V) at
IC101 pin 5?
Is Q170 normal?
Is D110 normal?
Is Q152 normal?
Replace F101(Use a specified
fuse).
NO
Replace BD101.
Replace R101.
Is D103 normal?
Check/
Replace D103
No 5.3V
Is F101 normal?
Check/Replace D109
No 12V
Is D109 normal?
YES
Is BD101 normal?
Replace D110
NO
YES
YES
NO
Replace Q170
NO
Replace Q152
NO
Check/ Replace Q163
YES
YES
YES
Is Q159 normal?
Check ‘H’ signal at Q161
Base terminal
Check/Replace D110
No 24V
Is D110 normal?
NO
Check/Replace Q152
NO
(3) No 24 V
Is D109 normal?
YES
NO
NO
Is L103 normal?
NO
Replace IC103.
Replace D109.
Is L103 normal?
YES
Is there about 2.5V at
IC103 pin 1?
YES
NO
Replace D106.
YES
Is D106 normal?
YES
Check the power terminal at main
PCB short.