Probook 4520s no backlight

[miha76]

Hello. I have Probook 4520 with UMA graphic which has backlight fuse blown.Can you please help me to locate that fuse so I can try to fix the motherboard.
Thank you.

[raajkumar]

Re: Probook 4520s no backlight

The fuse may be on back panel of the screen. You check it and before you install the fuse, you check the caps of that back panel for short circuit.

[miha76]

Re: Probook 4520s no backlight

Hello and thanks dor your answer. I tried with other working LED panela and got same result. So I assume its fuse on motherboard. Please advise.

[raajkumar]

Re: Probook 4520s no backlight

Do you have the schematic for this ? otherwise let me know the motherboard model.

[Jesse James]

Re: Probook 4520s no backlight

If you are lucky it is a fuse. Look for a F3 fuse on motherboard. When i check a backlight issue i measure voltages at screen connector with schematics as you will be missing a signal.
Post the m board info and you will probably get more help.
Hope this helps

[miha76]

Re: Probook 4520s no backlight

Hello. HP SPS are: 698667-001 and 606822-001
Also on a board is written: H9265-4 and 48 4GK06 041

[ktmmotocross]

Re: Probook 4520s no backlight

fuse is near lvds connector so it is not a problem to visualy find it

[miha76]

Re: Probook 4520s no backlight

fuse is near lvds connector so it is not a problem to visualy find it

Hell. I made a photo . Which one is F3 the big green or a small vertical element?

Photo: https://imgur.com/a/oGxUIOo

[ktmmotocross]

Re: Probook 4520s no backlight

1A/6V that could be it

[miha76]

Re: Probook 4520s no backlight

I saw that ona a bord. But which one is that? I don't have the other harfware from that laptop so I cannot try and power the board. I just need to know which one is correct so I'll try when I get other bits of that laptop.

[ktmmotocross]

Re: Probook 4520s no backlight

just measure its resistance

[SMDFlea]

Re: Probook 4520s no backlight

Check the pins on the connector for short,and resolder them with lots of flux .

[ktmmotocross]

Re: Probook 4520s no backlight

Check the pins on the connector for short,and resolder them with lots of flux .

it is easier to check that on fuse. it is directly connected too

[miha76]

Re: Probook 4520s no backlight

Check the pins on the connector for short,and resolder them with lots of flux .

Tnaks. I ahven0t notice that. It's brand new board which I sold to a custoer which returned it as faulyt-no backlight. So I assume he conected lcd cable when MB was under charge.

[raajkumar]

Re: Probook 4520s no backlight

Check this attached schematics. Check the voltages