32le5400 black screen

[xorium]

Hello all,

I got a Lg 32le5400 tv here with no picture on the screen.
I could not find any picture with a flashlight.
I opened the tv did not see anyting strange.
I opened the lcd panel i found some leds are on but very low brightness. (In the middle of the strip).

It has power supply 3pagc10017a-r.
I measured the voltage on the connecter from the power supply that run to the strips and get these results:
From top down

On p204
88
0
10.5
10
10.5
0
0
10.3
10.5
10.1
0
88

On p205
88
0
10.4
10.3
10.3
0
0
0
10.5
10
10.5
0
88

Are these voltages ok? Or is there someting odd because when i google i founs on a website that it should be 24 volts.

With kind regards

[vinceroger69]

Re: 32le5400 black screen

i have had a look for a schematic and cant seem too find one, if there is any writing by the connectors you have measured these voltages can you add the information to the voltages you have provided, that way we can see what each pin is supposed to be voltage wise etc.

[xorium]

Re: 32le5400 black screen



I wrote down the voltages in the first post
Hope the image is clear enough

[budm]

Re: 32le5400 black screen

We need the pictures of the whole backside of the TV showing how all the boards are connected together, then the pictures of the whole top and bottom side of this power supply/LED driver board.
We always insist on having the pin name and follow by the Voltage reading for each pin so we can easily see what each pin are fore without going back and forth between looking at the pictures and the reported readings.
Your reports in post 1 does not even have the pin numbers.

[xorium]

Re: 32le5400 black screen

On p204
#2.a =88
N.c = 0
#2-1 c =10.5
#2-2 c =10
#2-3 c =10.5
Nc =0
Nc =0
#1-3 c =10.3
#1-2 c =10.5
#1-1 c =10.1
Nc =0
#1.a =88

On p205
#4.a =88
N.c =0
4-1 c =10.4
4-2 c =10.3
4-3 c =10.3
Nc =0
Nc =0
Nc =0
#3-3 c =10.5
#3-2 c =10
#3-1 c=10.5
Nc =0
#3.a =88




Like this?

(The speakers are removed and the power buton and such.)

[xorium]

Re: 32le5400 black screen

This is picture of the leds.

[vinceroger69]

Re: 32le5400 black screen

in your bottom picture where the bottom centre mounting screw is there is some printing just to the left can you take a picture of that area so we can see what it says

[xorium]

Re: 32le5400 black screen

in your bottom picture where the bottom centre mounting screw is there is some printing just to the left can you take a picture of that area so we can see what it says

Mean this?

[vinceroger69]

Re: 32le5400 black screen

can you test all the voltages on p201 remember there are two rows of pins to measure

[xorium]

Re: 32le5400 black screen

can you test all the voltages on p201 remember there are two rows of pins to measure

these are the voltages i measure on the P201 connector:

nc = 0
12v = 12.18
12v = 12.18
12v = 12.18
gnd = 0
gnd = 0
3.5v = 3.42
3.5v = 3.42
gnd = 0
gnd = 0
20v = 18.79
on/off = 3.36


error = 0
pd1m = 0.6
nc = 0
drv_on = 0.07 to 0.08
vsync = 0
gnd = 0
3.5v = 3.42
3.5v = 3.42
gnd = 0
gnd = 0
20v = 18.79
20v = 18.79

[vinceroger69]

Re: 32le5400 black screen

Im not sure what this voltage should be
drv_on = 0.07 to 0.08
hopefully budm will have a idea i have been looking but cant find a schematic for this psu

[Dumah Brazorf]

Re: 32le5400 black screen

Maybe some leds are shorted causing the low 20V reading and tripping the rest of the tv. Other voltages before the led driver seem good.
I think you could check each led easily with a multimeter in diode mode.

[xorium]

Re: 32le5400 black screen

Maybe some leds are shorted causing the low 20V reading and tripping the rest of the tv. Other voltages before the led driver seems good.
I think you could check each led easily with a multimeter in diode mode.

How can i test them ?
i tried al combos with the 4 pins but no light. I found when i blow air on the leds they will go on for a short time. But not the normal brightness. I also tried the flashlight test again but i cant find any picture. Also tried to put hdmi in and in my laptop with sound on. Cant hear anyting. Dont know how to switch hdmi channel i tried to press input twice. And i pressed input once and used the arrows on remote. Dont hear any sound trough hdmi .

[Dumah Brazorf]

Re: 32le5400 black screen

Did the multimeter read something?
Maybe some clear coating on the pins?

EDIT: Found a service manual https://www.electronica-pt.com/esque...2le5400-25850/
EDIT2: wrong one...

[vinceroger69]

Re: 32le5400 black screen

Did the multimeter read something?
Maybe some clear coating on the pins?

EDIT: Found a service manual https://www.electronica-pt.com/esque...2le5400-25850/

service manual pdf

[budm]

Re: 32le5400 black screen

"drv_on = 0.07 to 0.08"
It looks like you are not getting the BL-ON to turn on the Voltage booster circuit to boost the Voltage up to drive the LED.
Rurn TV off, leave the black probe of the meter on the chassis, leave red probe CONNECTED to the #1A of the LED connector, turn the TV on and see if the Voltage will jump up over 100V or not.
Look at the OUTPUT VOLTAGE chart printed on your power supply board, I cannot read it well enough but it looks like it should be over 100V, you need to take closed up pictures of the chart.

[xorium]

Re: 32le5400 black screen

"drv_on = 0.07 to 0.08"
It looks like you are not getting the BL-ON to turn on the Voltage booster circuit to boost the Voltage up to drive the LED.
Rurn TV off, leave the black probe of the meter on the chassis, leave red probe CONNECTED to the #1A of the LED connector, turn the TV on and see if the Voltage will jump up over 100V or not.
Look at the OUTPUT VOLTAGE chart printed on your power supply board, I cannot read it well enough but it looks like it should be over 100V, you need to take closed up pictures of the chart.

When i turn the tv on it jumps to 88 volts.
Ans stays at 88 volts

You mean this printed on the power supply?
I geuss it should be 99 volts am i correct?

[budm]

Re: 32le5400 black screen

It looks like 32" LG panel will be 99V and the 32" AUOPTO panel is 61V.

[xorium]

Re: 32le5400 black screen

It looks like 32" LG panel will be 99V and the 32" AUOPTO panel is?? I cannot read the number.

61 volts

[budm]

Re: 32le5400 black screen

pd1m = 0.6

Dimming control is also way too low.
YOU may be able to simulate BL-ON and dim controls using resistors.