HP Pavilion g6, Backlight Not Working

[lebowitzit]

A customer of mine attempted to replace a damaged (LED backlit) display panel on a late model HP Pavilion g6-1d08x laptop. He subsequently brought it to me, and, seeing that he had mangled the connectors of both the display cable and screen, I ordered replacements for both. When I put it back together, the backlight would not work. I checked with a flashlight; the panel gets a good picture, but the backlight doesn't operate. It makes no difference whether I boot normally from the hard drive (Windows 7) or something else; the backlight won't even come on for the power-on self-test. It also does not respond to the keyboard hotkeys for turning the backlight up and down, whether or not Windows is running. If I plug the laptop into an external monitor, the picture is properly displayed on the external monitor.

The problem is, I have no idea how to determine whether the problem is the cable, the panel, the display connector on the motherboard, the lid switch, the BIOS or something else. I've tried two cables now (I thought the first was defective). Neither the old panel nor the new one will light up, although both display a picture that can be seen with a flashlight (the damaged one shows mostly lines and splotches, as you'd expect from a damaged LCD panel). I find it hard to believe that I have two panels with defective backlights or two bad cables. I don't know where the lid switch is, and the HP repair manual doesn't mention it. I don't have a supply of spare parts to swap in and out, and I don't know how to test the output of the motherboard display connector.

Can anyone provide some guidance? Many thanks!

 

[lebowitzit]

I finally gave up and brought the laptop to a repair shop. They had a compatible display panel that was known to be good, could not get it to work with this laptop and concluded that the problem is with the motherboard. The cost of a motherboard and the labor to install it, along with the parts and labor that I already put in, exceeds the cost of a new laptop of similar quality to this one, so it looks like this laptop is destined to be a mini-desktop - tethered to an external monitor - until it breaks again, at which point it will most likely be recycled.

 

[john ostdiek]

I have a HP G6 Pavillion model g6-1b79dx and sorry don't have a solution for you. I have the same trouble. I replaced the screen and it worked for six months and quit. The old screen was cracked but still was back lit. I put the old one back in and same thing not back lit. I tried to buy a cable but just got the wrong one off of ebay.
There are different versions or Model numbers of the HP pavillion G6. There are also different screens LCD or LED. Hope you have the right screen I almost bought the wrong one.Where did you buy your cable and what is the model number of your laptop? The screen model nuber is B156XW02

 

[lebowitzit]

My customer and I both bought the correct screen - the LED backlit version, in this case. The incorrect screen would not be plug-compatible, and the fluorescent backlit version requires an inverter board, which I would have recognized immediately.

Your screen model number doesn't really help to identify the correct display cable, because the display panels are actually fairly generic. (For example, the exact same screen as was purchased for the HP Pavilion G6 that I was working on also fit another customer's Lenovo ThinkPad SL510.) However, I looked up the hardware maintenance manual for your laptop, and according to it, the display cable you need is HP part number 639510-001. By doing a general web search for that part number, I found lots of places to buy it, including a number of eBay sellers. (I bought my cable on eBay as well.)

I wouldn't be so quick to blame the cable for the failure in your case, though. The reason I needed a cable was because my customer damaged the original cable while trying to replace the screen himself. But when it's installed properly, that display cable isn't subject to any noteworthy stress. If you had a machine to open and close the lid over and over again until something broke, the hinges or the switch that tells the computer that the lid has been closed would fail long before the cable would. I would confirm the operation of the lid switch first. (That's easy to do. Just put the lid back together, power the computer up, close the lid and if the computer goes to sleep, then the switch is working.)

 

[Angel Rijo]

I had the same problem and i found the solution to my problem, you may have similar or different problem who knows but anyways here is my solution.

Rijotech Solution!

 

[b-ray]

I had the same problem and i found the solution to my problem, you may have similar or different problem who knows but anyways here is my solution.
Rijotech Solution!

Hi guys, I have the same problem with a G6-1D44CA and can't seem to figure it out. It's definitely on the motherboard, which looks exactly like Angel's picture, but I don't have a schematic so I can't tell which part is for the backlight.

Angel, what did you do to fix the problem?