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A young kid came to my garage (house) where I have all kinds of computer things, he respectfully ask me to help him fix his computer, I know he doesnt have money to repair the Laptop and it is a nice Laptop, when I checked it out my eyes popped out to see if I could get the equipmet but Im not that way. Im honestly trying to repair the kids equipment, so I started taking screws from here from there, and from everywhere, right now the computer is completelly dissembled and I checked as much as I could to see if the LCD Panel had a fault visible but nothing appears to be obvious, the machine throws image when I connect it to a monitor but the LCD remains black, I noticed there is a circuit board on the bottom of the screen (which may be damaged) and I noticed that behind the LCD panel there is also a circuit board. Any good suggestions, I dont have the money to go and get another LCD panel to see if it works. Any tricks? Any gurus out there? Thanks a lot. Carlos Amaya Aguirre.

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Good direction from and good work so far . Because the laptop shows video on an external monitor, the fault is limited to the panel/backlight chain. The next steps are a short, safe checklist and a couple of practical tips that will let you narrow the fault without buying parts immediately.

First checks (no HV probing): power the machine and look closely at the LCD with a bright flashlight held near the screen. If you can see a faint image, the backlight or its driver is dead. If there is no image at all the LVDS cable or panel electronics may be damaged. Inspect the inverter board for obvious defects (burn marks, leaking or bulged capacitors, cracked solder joints) and carefully note any part numbers printed on the board or the white sticker on the back of the LCD panel — those numbers are what you will use to search for replacements. Remove the inverter from the panel and test suspect small parts (fuses) for continuity with a multimeter while the board is unpowered.

Safe voltage checks: measure only the low-voltage input pins at the inverter connector (the DC supply and the BL_ON or enable line) while the laptop is powered. Do not probe the high-voltage outputs to the lamps; those can give a painful shock. If the inverter is receiving its enable voltage but the lamps do not light, the inverter board itself is the likely culprit.

If you post photos, include: a clear full-photo of the inverter PCB, a close-up of the small SMD area where a fuse might sit (with a ruler for scale), the LCD panel sticker with model numbers, and a shot of the inverter connector on the cable. Good, in-focus images let others identify the right fuse or a replacement inverter board. If the board looks intact but there is no enable voltage, the problem may be upstream on the mainboard and that requires a different approach.

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Member Avatar for Rik_

The circuit at the bottom of the screen is the backlight inverter. It is most likely that that is at fault.
The backlight inverter will have a surface mount fuse on it, it's most likely that that has failed. You can test it's continuity with a digital volt meter. DO NOT use the volt meter on the inverter while it's powered or you will get a really nasty shock.
A surface mount fuse can usually be replaced for just a few pence provided you can solder!

Edited by Rik_ because: n/a
Member Avatar for spc40210

I will upload an image of the backlight inverter, but first I will try to locate the fuse that you tell me about, if im unable to find the fuse I will ask you for help again, you have been great help and the kid will surely will be real happy. Im in Mexico city, and I studied Associate Degree in Computer Science in WA, St. USA, I want to make many friends from the USA because I love people from overthere. Thanks again RIK.

Member Avatar for Rik_

In order to indentify the fuse it will need to be a very clear picture!

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