42PFL7406 No Power

[budm]

Re: 42PFL7406 No Power

This is what iam getting with 1K present

OK, so running the power supply board by itself and use force on the PFC Boosted Voltage is present and did not drop out.
3.3V standby Voltage is present and steady as reported earlier by OP.
12V is steady?
24V is steady?

If they are all the steady, then the next step is to force on the backlights circuit.

[trunks81]

Re: 42PFL7406 No Power

all readings are stable 12/24/3.3

[budm]

Re: 42PFL7406 No Power

all readings are stable 12/24/3.3

Good.
So before we force the backlights on, I need to know the Voltages at CN4 first.

Connector CN4:

Pin 9 BL-ON/OFF =
Pin 10 BL-DIM =
Pin 11 BL_I_CTRL =
Pin 12 POK =

[trunks81]

Re: 42PFL7406 No Power

Iam getting the next values


Pin 9 BL-ON/OFF = 0.0010
Pin 10 BL-DIM = -0.0236
Pin 11 BL_I_CTRL = -0.0116
Pin 12 POK = -0.0158

[budm]

Re: 42PFL7406 No Power

Iam getting the next values


Pin 9 BL-ON/OFF = 0.0010
Pin 10 BL-DIM = -0.0236
Pin 11 BL_I_CTRL = -0.0116
Pin 12 POK = -0.0158

OK, you will need a 1K (It may have to less if wen cannot get >2V on this pin using 1K) between BL_ON/OFF and 3.3V.

you will need a 1K (It may have to less if wen cannot get >2V on this pin using 1K) between BL_Dim and 3.3V.

This should force on the backlights.
You still need that 1K for the PS-ON to GND.
So you need 3 resistors.

[trunks81]

Re: 42PFL7406 No Power

oke when doing that.. the backlight goes on
Also did an test i connected one 12V light to the 12V and one to the 24V both are burning without flickering (12V 7W)

[budm]

Re: 42PFL7406 No Power

oke when doing that.. the backlight goes on

Let it run for 5 minutes to make sure it will stay running.

[budm]

Re: 42PFL7406 No Power

BTW, what do you get on these pins now while the board is running?
Connector CN4:

Pin 9 BL-ON/OFF =
Pin 10 BL-DIM =
Pin 11 BL_I_CTRL =
Pin 12 POK =

[trunks81]

Re: 42PFL7406 No Power

hello did an other test when connected an 12V 7W to the 3.3v it also is stable
And second iam unable te get the BL running again with the resistors

[budm]

Re: 42PFL7406 No Power

What do you get on these pins now while the board is running?
Connector CN4:

Pin 9 BL-ON/OFF =
Pin 10 BL-DIM =
Pin 11 BL_I_CTRL =
Pin 12 POK =

"And second iam unable te get the BL running again with the resistors"

Are you saying now that the Backlights are not on any more?

[trunks81]

Re: 42PFL7406 No Power

Iam getting the next values.. tested again with an 100ohm 5 watt

Pin 9 BL-ON/OFF = 3.29V
Pin 10 BL-DIM = 3.29V
Pin 11 BL_I_CTRL = 2.4108V
Pin 12 POK = 3.3102V

And this time the BL comes on again and stays on !

Also i tested 4778 on the M/B and between S-G iam getting 12,54 ohm

[trunks81]

Re: 42PFL7406 No Power

When 7u01 soldered of the board iam getting OL

[trunks81]

Re: 42PFL7406 No Power

i replaced u701 and now the tv blinks twice