SECONDARY POWER SUPPLY SECTION TROUBLESHOOTING
Confirm that 'P' board is good. Confirm voltage at R870 & R873 (3V). If not good, check [R858, R860, R871, R872, R859, R861, R873, R874, R899, D841 & D842]. If found OK;
Confirm the Power Control Signals from IC1106.
- MAIN_ON: [H] 2.4V, [L] 0V : Pin-39 of PAP2.
- SUB_ON : [H] 2.4V, [L] OV: at Pin 38 of PAP2
- PANEL_ON: [H] 2.4V, [L] 0V: at Pin 32 of PAP2
Confirm the power control signals from IC7501
- P_ON_H: [H] 5V, [L] 0V: at Pin 15 of PAP6
- DR_P_ONH: [H] 5V, [L] 0V: at Pin 16 of PAP6.
If the above stated conditions are not good, check IC1106 on 'DG' board & IC7501 or 'RD' board.
If the above stated conditions are good: Confirm Power Control Signals to each of the regulators.
MAIN_ACT
|
[H] 2.4V, [L] 0V
|
SUB_ACT
|
[H] 2.4V, [L] 0V
|
PANEL_ACT
|
[H] 2.4V, [L] 0V
|
DR_P_ON_ACT
|
[H] 2.4V, [L] 0V
|
P_ON_ACT
|
[H] 2.4V, [L] 0V
|
If not good check each diode & transistor:
MAIN_ACT
|
D830, D856
|
SUB_ACT
|
D832, D857
|
PANEL_ACT
|
D835, D858
|
DR_P_ON_ACT
|
D834, D860, Q828
|
P_ON_ACT
|
D831, D859, 1827
|
If all stated above are good, confirm the output voltage from each regulator IC. If not good, replace the respective regulator IC.
If all are found good, there is no problem to the Secondary power Supply.
