PHILIPS 75PUS7805/12 BLACK SCREEN

[bohaboha]

Hi lotas and thank you so my test procedure was wrong then how should i test it black probe to C8622NC and the red probe to VLED+ if I have understood correctly?

Hello everyone after a difficult time of illness now I am ready and count on your support. Now I have got the new backlight for this huge TV that is on the bed as you can see.
Is it normal that it should read 42.3V with all the lights on this is when I test with backlight tests regardless of whether it is two rows that are tested or the whole set.
but when i connect everything together without putting the tv together and turn on all the lights are on but very low light and of course i don't expect that you would see any picture of the low light intensity.
I get very doubtful is there anyone who can give an explanation
Thanks in advance

[bohaboha]

The backlight is never connected to the common ground! Power + is constantly supplied to the backlight connector, and - (negative) is disconnected, adjustable, controlled by the backlight drivers via mosfets. Here is your connection diagram...

Hello everyone after a difficult time of illness now I am ready and count on your support. Now I have got the new backlight for this huge TV that is on the bed as you can see.
Is it normal that it should read 42.3V with all the lights on this is when I test with backlight tests regardless of whether it is two rows that are tested or the whole set.
but when i connect everything together without putting the tv together and turn on all the lights are on but very low light and of course i don't expect that you would see any picture of the low light intensity.
I get very doubtful is there anyone who can give an explanation
Thanks in advance

[lotas]

Your backlight is connected in series - parallel (several channels are connected in parallel), connect and connect everything without a panel and supply power and see how the diodes will light up from the standard power supply.

[Diah]

at his first Post. he stated only ambient on, no Picture no sound... so what had this to do with LED BL ?
his set had FRC function on main boards... this much likely Philips known fault chassis TPM206Eas Glitch at firmware .. need upgrade_loader.plg firmware to flash via USB formatted FAT32 in MBR Mode.

[bohaboha]

Your backlight is connected in series - parallel (several channels are connected in parallel), connect and connect everything without a panel and supply power and see how the diodes will light up from the standard power supply.

Hi lotas and thank you . Here what i get Screen and Tcon not connected but mainboard and of course power supply are connected the light is very dim sorry i have a problem to upload pictures just now i do it as soon i solve it but i hope you understand

[bohaboha]

at his first Post. he stated only ambient on, no Picture no sound... so what had this to do with LED BL ?
his set had FRC function on main boards... this much likely Philips known fault chassis TPM206Eas Glitch at firmware .. need upgrade_loader.plg firmware to flash via USB formatted FAT32 in MBR Mode.

Hi Diah it is true what you say but afterwards I discovered that there was a picture but no sound and I got sick and forgot to update you guys Sorry.
but thanks for the information and reference it will surely be of use in the future

[Diah]

Hi Diah it is true what you say but afterwards I discovered that there was a picture but no sound and I got sick and forgot to update you guys Sorry.
but thanks for the information and reference it will surely be of use in the future

T-CON must be connected to MB then the LED BL will turn full current, no need to LCD.

[bohaboha]

T-CON must be connected to MB then the LED BL will turn full current, no need to LCD.

even with Tcon connected the LED BL same result is it possible it is not the right LED? I bought from : hhhelectronic
on ebay and he say that they are ok for this model
LED-Streifen Für 75PUS7354 75PUS7805 75PUS7855/12 CEJJ-LB750Z-8S1P-M3030-J-1 K-1 #388116982118

Inkorgen

[bohaboha]

Hi lotas and thank you . Here what i get Screen and Tcon not connected but mainboard and of course power supply are connected the light is very dim sorry i have a problem to upload pictures just now i do it as soon i solve it but i hope you understand

Here are the pics

[Diah]

messure the LED BL Socket on PSU, the red cable with reference TV chassis , turn on and tell the high and low Voltage you have

[bohaboha]

messure the LED BL Socket on PSU, the red cable with reference TV chassis , turn on and tell the high and low Voltage you have

Hi as you did not mention any tester i used my multimeter for this test here there are the yellow probe on chassis is the red one

[Diah]

Hi as you did not mention any tester i used my multimeter for this test here there are the yellow probe on chassis is the red one

you did this measurements only on RED cable right ? its strange reading ... can you tell yours original Strips, how many pieces and how many LED on each strip.. if you can show the wiring of the strip where they are fitting on chassis

[Diah]

write also the original Strips the printed label , the replacement we can see they are 3030 LED, there are 2 type double LED and single one..

[bohaboha]

you did this measurements only on RED cable right ? its strange reading ... can you tell yours original Strips, how many pieces and how many LED on each strip.. if you can show the wiring of the strip where they are fitting on chassis

there is 16 on each hole row all together 128 LEDS
for the measurement i did it for red and black and the result for the Red is the higher value
here is the backlight Data

[Diah]

original also 3030, use yours LED tester to light on just one LED from Original and replacement then compare the light strong and V and current

[lotas]

You have all 8 LED strips connected in parallel, that is, they have one plus and one minus. If there are 16 LEDs in a strip, then 16 x 3v = 48v (the same as what your power supply supplies to the LEDs), and the brightness depends on the current strength.