Re: 17IPS20 Toshiba 40L3441DG Backlight

Now it's working. I cut the BL-ON-OFF cable and connected it on the PSU-side to the PWM pin. It doesn't work in some picture modes, but i don't need them.

Re: 17IPS20 Toshiba 40L3441DG Backlight

I tried this before and it changed nothing.

Re: 17IPS20 Toshiba 40L3441DG Backlight

I connected the ground from the backlight with the chassis and i added a switch to the BL-ON-OFF cable. It works until i plug in any HDMI cable. Didn't tried any other source. then the backlight turns of again and it don't help switching the BL-ON-OFF(if lights up for a second). It also turns of if i go to deep into the settings

Re: 17IPS20 Toshiba 40L3441DG Backlight

then i will use a switch. Since this TV will stay on the desk next to me its no problem to turn him on with a switch. Thank you for your help.

Re: 17IPS20 Toshiba 40L3441DG Backlight

I connected the red cable from my multimeter to the red cable going to the backlight

When i connect the black cable to the chassis then i get 157V (157V/45 = 3,49V) and it drops slowly to 78V

When i connect the black cable to the black cable for the backlight then i get 108V (108V/45 = 2,4V) and it drops slowly to 29V

I tried to connect the black cable from the backlight to the chassis = same reaction.
But if i reconnect the BL-ON-OFF cable the lights stay on. I read then 130V (130V/45 = 2,89V)...

Re: 17IPS20 Toshiba 40L3441DG Backlight

The lights on the first and on the last strip are aligned in an other way. The inner strips have the same distance between the leds, but the outer strips have at the begin and the end shorter distances and in the middle longer distances.

Re: 17IPS20 Toshiba 40L3441DG Backlight

the problem is that every LED is working. I was luckly able to make a picture of the flashing lights....

I got this TV from a friend. It was dead(No power LED). He says it worked just fine until he coudn't turn it on. I measurred the output voltages from the PSU but there nothing.
Then i buyed a new one from eBay. The panel works and the motherboard too.
Then i turn it on with the new power supply the backlight turn on for a second or less and it turns off again, but the image is visible with a flashlight.
I opened the screen to see if there are some damaged LEDs. All LEDs are working(for less than a second).
If i pull the BL_ON-OFF cable out from the connector the backlight...

Re: New Members - please post your introductions here

Hello from Germany,
im new in this forum and i repaired a few computers and a monitor i the past.
Now i need to repair a TV and i hope i can find some help here.

Alexander