sony vaio vgn-sz3xwp/c backlight not working

[zeeky2004]

I am trying to fix a Sony Vaio vgn-sz3xwp/c with a faulty backlight at the moment but I cannot figure out what is wrong, this laptop seems kind of rare as I cannot find much information about repairing it on the internet. The person who owns it said that one side of the screen wasn't lit but when I took it home neither side of the screen was lighting up. This model confused me because it does not have an inverter under the screen like most laptops, while looking for an inverter board I only found 1 on the entire internet which is sort of triangle shaped and connects to the motherboard next to the screen cable connector, replacing it with a known working one did not work.

I read somewhere that there are sometimes surface mount fuses on the back of the motherboard which if blown can cause the backlights to not get any power but I looked over the entire motherboard and could not find anything, I tested a few things that resembled fuses but they were all fine.

I'm going to order a new screen cable and see if that works but does anyone else have any suggestions? Are there any known issues with this model of laptop or similar models which causes the backlight to stop working?

[Blencogo]

Hi zeeky2004 and welcome.

As you found out, this model has a LCD display and has a DDC-5 Daughterboard instead of the inverter found with older models.  I presume this is what you have replaced.

I haven't heard of any other similar problems with this model, so I guess checking the LCD Harness and its connections is the best bet.  The harness does get twisted inside the hinge.

After that, the screen itself may be suspect as I don't think there are any surface fuses.

[zeeky2004]

Well replacing the screen cable did not fix it either so it's either a motherboard or screen problem. I have just noticed that on the long circuit board under the LCD pannel there is some corrosion around one of the connectors for the LED backlight so I think the problem lies with the screen.