Telefunken d48u300n4cw with sound and picture but no backlight

[vigorcent]

Re: Telefunken d48u300n4cw with sound and picture but no backlight

Well now this is really strange... I didn't see that, thanks for pointing that out.
No, it is not a burned component, but there initially was one. This is the power supply I bought from the replacement store. In fact, the component wasn't removed, but moved to the left. I'll post a picture for comparison.

On the left is my old psu that was originally built into the newly bought TV. This psu didn't show the initial backlight flash (and voltage peak at led pins) when turning on the TV.

On the right is the replacement psu I bought last week.

This means that pin 6 is connected to the MP3394 and not pin 7, whereas pin 7 leads to led- of the upper led strip group and pin 6 doesn't even have a wire. I need to leave the house again. When I'm back, I'll have a look if I find anything else that's different.

[dick_barton]

Re: Telefunken d48u300n4cw with sound and picture but no backlight

So the power supply on the left is the original one that came with the tv when it was new.
If that is the case then you would need to alter the replacement power supply so that it matches you original power supply.

As you say the boards do not match and the connection from pins 8 & 9 of the MP3394 do not go to the same pin of the led connector and that is probably what is at fault.

[vigorcent]

Re: Telefunken d48u300n4cw with sound and picture but no backlight

I will try to move this component and will let you know tomorrow.

[vigorcent]

Re: Telefunken d48u300n4cw with sound and picture but no backlight

It's working now! Only thing is that there is a loud buzzing sound when I'm using specific picture presets or at low backlight settings, but It will do for now.
Thank you so much for your help, dick_barton! I wouldn't have found the issue on my own.

[dick_barton]

Re: Telefunken d48u300n4cw with sound and picture but no backlight

No; it was a team effort and youdid spot the cross over 0 ohm resistor going to the wrong led connector pin.

Do not forget to lower the backlights down as low as possible to provide a longer lifespan for your leds.