LG HT903WA Service Manual page 14

5. Test & debug flow
Test
Check the
AC voltage Power PCBA (110V
or 220V).
Switch on the Power PCBA.
Are the DC
Voltage outputs OK? (-34V, -28V,-32V, ±12V, 3.5V,
5.6VA, 5V, 7V).
Are 3.3V and
5V DC outputs normal on main
PCBA?
Update
FLASH successfully?
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Only for training and service purposes
YES
YES
YES
YES
YES
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 system reset circuit.
NO
3. Check FLASH R/W enable signal PRD,
RWR.
4. Check FLASH Memory related circuit.
2-5
NO
Replace FLASH.
LGE Internal Use Only