Hp 650 lcd backlight problem

[Stanislav Rago]

Hello guys. I have a Hp 650 laptop which display recently turned completely black. So I started to look for a solution and found that lcd backlight doesn't work. If I look closely on display with flashlight I can see Pc booting just fine. Same thing when I connect external monitor it works just fine. So I told to myself, fine its probably backlight inventer. When I opened it I have realized that this model doesn't have inventer. What do you guys think? Is there any fix for this problem or it's just faulty motherboard?

Thank you,
Best regards

 

[jarotech]

Hi, you could have only one of three things defective for this problem, one, the cable for your screen, two, the screen itself, and third the motherboard would be defective.

 

[Stanislav Rago]

Yea, well I changed new display and had same problem. So I guess that eliminates cable and screen itself. I was hoping its not faulty motherboard. Thank you for response.

 

[jarotech]

So you change the screen and the cable too? You have an inductor (L4) on the motherboard which allows the voltage to pass for the backlight, perhaps the inductor is open.

 

[Stanislav Rago]

I have changed only display not the cable (Idk if I can even find that kind of cable). And as far as inductor I can't say because I'm newbie at electronics.

 

[jarotech]

This is the part number for the cable : 686256-001. Before replacing the cable, if you can find the inductor L4 near the connector for the screen on the motherboard, you can simply short the inductor, that way if the backlight come back, meaning the inductor is defective. But be careful to not short anything else.

 

[Stanislav Rago]

This cable you speak of, I cannot find it for my model. Does it fit for from other models ?

 

[jarotech]

This cable is not the same one you have in your laptop?

http://www.ebay.com/itm/HP-650-655-LED-Screen-Cable-New-/281494123550?hash=item418a5b741e:g:MXgAAOxy039TLZHs