System Test Flow - LG DKC880 Manual

3. SYSTEM TEST FLOW

TEST
Check the AC Voltage
Power PCBA(110V or 220V)
Switch on the power PCBA
Is the DC voltage outputs OK?
(5V, 3.3V, 12V, 5.6V MOTOR)
Make sure the main PCBA don't
short on VCCs and switch it on.
Is 3.3V and 1.8V DC outputs
normal on main PCBA?
Connect to PC RS232 cable and
update the FLASH memory code.
Update FLASH successfully?
A
YES
YES
YES
YES
YES
NO
Replace power PCBA or AC transformer.
NO
Repair or Replace Power PCBA
NO
Check the regulators or related diodes.
NO
1. Check 27MHz system clock.
2. Check system reset circuit.
3. Check FLASH R/W enable signal PRD,
RWR.
4. Check RS232 SIGNALS.
5. Check FLASH Memory related circuit.
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