Urgent help needed locating LED fuse on Toshiba L750

[Revrecords]

Hi all.

I have a Toshiba Sattelite L750 (part no. PSK2YA-04P028) with no backlight. I have tested it with an external display which was fine. I have also tested it with another LED panel and cable which gave the same dim display with no backlight.

I suspect that it is a blown fuse on the motherboard but I cant locate it.

I have attached a couple of pics of the motherboard.

If anybody would be kind enough to identify the culprit(s) for me it would be very much appreciated.

[layad]

Re: Urgent help needed locating LED fuse on Toshiba L750

check the inverter

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Other side of board.

Any help would be great cheers

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Thanks for the quick reply.

Being an LED panel it doesnt have an inverter, to my knowledge. Is that right?

[layad]

Re: Urgent help needed locating LED fuse on Toshiba L750

oh sorry this laptop has no inverter, its led one

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

Hi all.

I have a Toshiba Sattelite L750 (part no. PSK2YA-04P028) with no backlight. I have tested it with an external display which was fine. I have also tested it with another LED panel and cable which gave the same dim display with no backlight.

I suspect that it is a blown fuse on the motherboard but I cant locate it.

I have attached a couple of pics of the motherboard.

If anybody would be kind enough to identify the culprit(s) for me it would be very much appreciated.

make a macro picture of the LCD connector

[khaahk]

Re: Urgent help needed locating LED fuse on Toshiba L750

Locate R858, that should act as fuse for BL voltage.

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Thanks for the reply dj. This pic ok?

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Locate R858, that should act as fuse for BL voltage.

Thanks khaahk. Im not having much luck finding R858 though. Any idea roughly where it might be located?

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

circle nr1 thats PF2 that`s a fuse- Go! check it
circle nr2 macro pic so we can see better.

p.s. we assume that you change the cable and screen...right?


nvm that bat+ fuse ... just check it

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

check the voltage on all the pin i show you and post back
cable connected and lcd with power (live)

be careful!!

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

circle nr1 thats PF2 that`s a fuse- Go! check it
circle nr2 macro pic so we can see better.

p.s. we assume that you change the cable and screen...right?


nvm that bat+ fuse ... just check it

Heres the macro pic of nr2.

About to check the fuse etc. now. Will post results asap.

Thanks heaps for your help mate

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

check the voltage on all the pin i show you and post back
cable connected and lcd with power (live)

be careful!!

Test results:

LCDVCC = 0v (both points)
+3v = 3.2v
LVDS_VADJ = 2.92v
DISPON_O = 0v
LCD_BK_POWER = 18.84v (both points)

PF2 fuse = 0ohms

Again, your helps very much appreciated dj

[khaahk]

Re: Urgent help needed locating LED fuse on Toshiba L750

Without LCDVCC you shouldn't even have picture on panel.
If LCD_BK_POWER is 18V, then there is no fuse problem.
Either you have LID switch faulty or dead EC.
How did the problem start? Did somebody change the screen with battery connected?

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

Test results:

PF2 fuse = 0ohms

what voltage do you have on that fuse on both sides?

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Without LCDVCC you shouldn't even have picture on panel.
If LCD_BK_POWER is 18V, then there is no fuse problem.
Either you have LID switch faulty or dead EC.
How did the problem start? Did somebody change the screen with battery connected?

No. A glass of water was spilled on it. It was closed at the time, but from what I can tell some of the water got into the internals through the hinge gaps. It wasn't much, but enough to cause some problems.

[khaahk]

Re: Urgent help needed locating LED fuse on Toshiba L750

I think you got water damage in that place.

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

I think you got water damage in that place.

No!
i think its from the flash

[dj_ricoh]

Re: Urgent help needed locating LED fuse on Toshiba L750

lets start!
NPCE791LA0DX U7 pic1 PIN 6 its DISPON_O -voltage

and pic 2 - find Q18 on the motherboard and post the voltage.

we will go from there.

did you try another screen or test your screen another notebook?
cable ?

[Revrecords]

Re: Urgent help needed locating LED fuse on Toshiba L750

Apologies for the delayed response. The owner of the system has decided to replace rather than repair.

Many thanks to those who offered assistance.