Pcb Failure - Samsung NV75N7570RS Service Manual

4-2-11 PCB Failure

PCB Failure
- Check the input voltage of
PCB SMPS
(input checkpoint : 230~240V )
YES
- Check the output voltage of
PCB SMPS (Output check-
point : 5V/12V )
- Do all relays operate?
NO
- Check the operating base
voltage(5V) which is appro-
priate for each relay.
NO
Replace PCB
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NO
- TCO Open?
- Check Terminal block
voltage(230~240V).
Reset the circuit braker or
check main power.
NO
- Check fuse protecting SMPS
Replace PCB
YES
• After Lamp On
- Safety Relay
Contact point ON(12V)?
YES
YES
Replace Relay
YES
NO
YES
NO
NO
YES
NO
- 34 -
Replace TCO
Repair Faulty wiring
or PCB check
Replace FUSE
Replace PCB
YES
- Check the operating Base
voltage(0V) of Safety
Relay.
YES
Replace Safety Relay