Sanyo LCD-42XR7H, Service Manual

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37
Troubleshooting guide
1. Trouble diagnosis of power
2. No DC output
No power
Check if C539
has 5V
Yes
No
Check N503
Check if C533
has voltage over
100V Yes
No
Check N501 and its periphery (include
transformer and the secondary sample
feedback circuit.
Check the fore
circuit of fuse
and rectifier.
No DC output
(Vsb normal)
Check 32VSC,
5VSC
No
Check if Standby
is high level
Yes
Check if 24VCF,
24VSC, 18VSC
is normal Yes
No
Check N504 and
the correlative
circuit
Yes
Check the fore
circuit
No
Check the
correlative circuit
Check if the voltage of
C533 is about
395V(less than 370V is
abnormal)
Yes
No
Check L6563 and its
periphery (include
the VCC)
Check N512 and its periphery
(include VCC, transformer
and the secondary sample
feedback circuit)