Test & Debug Flow - LG LH-W551TB Service Manual

2. Test & debug flow
TEST
Check the
AC Vol tage
Power PCBA (110V
or 220V)
Yes
Switch on the Power PCBA
Is the
DC Voltage
outputs OK? (-44V, -22V,
-26.5V, ±12V, 5.6V, 3.3V,
5V, 7V, 8V)
Yes
Are 3.3V and 5V DC
outputs normal on main
PCBA?
Yes
Update
FLASH
successfully?
Yes
A
No
Check the POWER PART
No
Check the POWER PART
No
Check the regulators or diode.
1. Check 27MHz system clock.
2. Check systemreset circuit.
No
3. Check FLASH R/Wenable signal PRD,
RWR.
4. Check FLASH Memory related circuit.
Replace FLASH
3-2