Proscan 50" PLDED5066A-E no backlights

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Close up

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

I check all of the board and nothing is brown or brownish under a magnifying glass

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

OK, I need clear straight shot pictures of the two sections I mark, you will need to remove that white plastic plastic so I can see the traces.

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Pic

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Thank you for the help

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

I don't know if you saw this pic of the voltage readings and don't know if this means anything but it has voltage going into L2 but nothing coming out

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

I don't know if you saw this pic of the voltage readings and don't know if this means anything but it has voltage going into L2 but nothing coming out

I need to trace out the circuits, so I am looking at the closed up pictures I requested to get some ideas how it works.

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

https://www.badcaps.net/forum/attach...9&d=1448074584
This one is cut off on the top, I am trying to see how the small green daughter board pins are connected to the main power supply board.

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

OK, I found pictures of the board AY128D-4SF51 which looks really close to your board AY128D-4SF11.
As you can see, CON3 has the pin labels on the bottom side of the board, so I need to know what the Voltages are (yo post the Voltage readings but did not assign pin numbers or the pin name with the readings).
I need to find out if you do have >2.5VDC on pin 5 (PS-ON) or not, and the Voltage readings of the rest of the pins.
Pictures provided by SHOPJIMMY.
1 (GND)
2 (GND)
3 (+5V) =
4 (+5V) =
5 (PS-ON) =
6 (+5VSB) =
7 (+5) =
8 (+5) =
9 (GND)
10 (GND)
11 (GND)
12 (+12V) =
13 (+12V) =

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

1 (GND)
2 (GND)
3 (+5V) =5.02v
4 (+5V) =5.02v
5 (PS-ON) =4.42v
6 (+5VSB) =5.04v
7 (+5) =5.02v
8 (+5) =5.02v
9 (GND)
10 (GND)
11 (GND)
12 (+12V) =11.90v
13 (+12V) =11.90v

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Pics

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Ic 1

[CapLeaker]

Re: Proscan 50" PLDED5066A-E no backlights

I don't know if you saw this pic of the voltage readings and don't know if this means anything but it has voltage going into L2 but nothing coming out

Take the transformer out and check it. Maybe it is open (thermal fuse inside the transformer)?

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

You do have PS-0N but you do not have PFC boosted Voltage to run the LED driver circuit, you must get the Boosted Voltage first.

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

Any suggestions where or how to look for it?

[CapLeaker]

Re: Proscan 50" PLDED5066A-E no backlights

the 400V main filter cap (that looooong skinny cap). Just be careful not to short or touch anything on the primary.

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

So verify the DCV again by measuring between the two legs of the main filter cap when TV is powered on to see what you have.

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

384.0 V. It appears I loose the voltage on L2

[budm]

Re: Proscan 50" PLDED5066A-E no backlights

L2 is the PFC inductor, the PFC and L2 are OK otherwise you will not have the 384V DC on the cap.
https://www.badcaps.net/forum/attach...0&d=1448075181
In the picture you show 173VDC on C13, you had indicated you were using the negative leg of the as the GND ref for the meter in post 1., but now you have 384VDC.

[mnpdreed]

Re: Proscan 50" PLDED5066A-E no backlights

I'm sorry I guess I posted it incorrect it is 384 v. Sorry for confusing you.