How to troubleshoot a “no power condition for the TH-42PX25U
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 3
40
Summary of Contents for GP6DU
Page 6: ......
Page 8: ...2 ...
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Page 18: ...12 ...
Page 20: ...14 Figure 7 Video Block Diagram ...
Page 21: ...15 Figure 8 H Board Block Diagram ...
Page 22: ...16 ...
Page 23: ...Figure 9 H Board Block Diagram 17 ...
Page 24: ...Figure 10 DG Board Block Diagram 18 ...
Page 37: ...Figure 23 TH 42PD25U Power on operation 31 ...
Page 38: ...32 ...
Page 40: ...34 ...
Page 42: ...36 ...
Page 43: ...DG6 DG3 Figure 24 TH 42PX25U Power on operation 37 ...
Page 45: ...Figure 25 TH 42PX25U P Power on operation 39 ...
Page 49: ...4 1 Figure 26 TH 65XVS30 Power On operation 43 ...
Page 54: ...48 ...
Page 55: ...49 Figure 28 TH 42PD25U PA board SOS detect ...
Page 56: ...50 ...
Page 59: ...Figure 31 SS board SOS Detect 53 ...
Page 62: ...56 ...
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Page 72: ...66 ...
Page 74: ...68 ...
Page 87: ...IC9709 Figure 36 TH 42PX25U 3 3V_SOS_5V_SOS detect 81 ...
Page 89: ...Figure 38 SS SOS Detect 83 ...
Page 90: ...84 ...
Page 94: ...Figure 40 3 3V SOS and 5V SOS Detect Circuit TH 42XVS30 88 ...
Page 95: ......
Page 97: ...Figure 42 SC SOS Detect Circuit TH 42XVS30 91 ...
Page 100: ...94 ...
Page 101: ...Figure 44 Power SOS and Fan SOS Detect Circuit TH 42XVS30 95 ...
Page 102: ...96 ...
Page 103: ...TH 42XVS30 4X 3X 2X 7X 9X 5X 12X Figure 45 97 ...
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