User manual

33
How to troubleshoot a “no power condition for the TH-42PD25U
Is the power LED red at power up?
Yes No
Does the voltage at pin 2 of P27 go high when power is
turned on?
Yes No
Is 5V present on pin 4 of connector P27 on
the P board?
The P board is
possibly defective
Is the voltage high at pin 9 of PF10
on the PF board?
Yes No
Yes No
Check the K and
PA boards
Is there AC going in to
pins 1 and 4 of
connector P9 on the P
board?
The D or the DG
board may be
defective
Is there 10V on pin 1, and 24V
on pin 5 of connector PF10 on
the PF board?
Yes No
Yes No
Replace
the P
board
If fuses
on the PF
are ok,
the PF
board
Can you confirm these voltages at connector
PA12 on the PA board?
3 7 11 17 21 25
5V 5V 5V 10V 9V 2.5V
The PF
board
may be
the
problem
Yes No
Check the D and the
DG boards
Check The PA board
Table 2