Burning Out My Display

[QrazyQuadQore]

So I was trying to put in a new display into my laptop, an HP Elitebook 8740W, I thought ok new one has 40 pin connector and my old one has 40 pin connector, so it should work right? Nope, new display has 2 burnt out IC's and my old display which was working alright-has no backlight now. These are LED screens so there is no voltage module to power CCFL'S, just a cable from the MB to the 40 pin connector and thats it.

So since my screen had a backlight before, and now doesnt, after trying to install the new one, along with a nice burnt smell. I dont see any reason the old screen could have burnt out and leaves me to think I have a burnt up cable or a blown fuse/IC/cap/resistor/diode ect, on the motherboard possibly? Anyone heard of this, or know anything about this, hard way to learn.

Additionally if I get another Elitebook and swap the internals out pending worst case no solutions, will windows still work, I know it can get picky with MB swaps, but the chipset and everything else will be the same.....cpu, gpu, blu-ray, wireless modules, keyboard, new MB ect.

P.S this is my first time on TechPowerUp Forums, I hope I got this in the right place....and GPUZ rocks btw

 

[eidairaman1]

Take both and make 1 good one

 

[Jetster]

So I was trying to put in a new display into my laptop, an HP Elitebook 8740W, I thought ok new one has 40 pin connector and my old one has 40 pin connector, so it should work right? Nope, new display has 2 burnt out IC's and my old display which was working alright-has no backlight now. These are LED screens so there is no voltage module to power CCFL'S, just a cable from the MB to the 40 pin connector and thats it.

So since my screen had a backlight before, and now doesnt, after trying to install the new one, along with a nice burnt smell. I dont see any reason the old screen could have burnt out and leaves me to think I have a burnt up cable or a blown fuse/IC/cap/resistor/diode ect, on the motherboard possibly? Anyone heard of this, or know anything about this, hard way to learn.

Additionally if I get another Elitebook and swap the internals out pending worst case no solutions, will windows still work, I know it can get picky with MB swaps, but the chipset and everything else will be the same.....cpu, gpu, blu-ray, wireless modules, keyboard, new MB ect.

P.S this is my first time on TechPowerUp Forums, I hope I got this in the right place....and GPUZ rocks btw

It will work but your license will not be active any longer. But you can call MS and go through the mega number activation. I would probably sell all of it on e bay as is. Does it work with an external monitor?

I hate laptops

 

[QrazyQuadQore]

Can you explain the MS validation crapola, the Elitebook essentially uses the same parts, just the MB will be different serial numbers and such. And a different screen, chassis. Drivers shouldnt have to change or anything.

As for the other guy I already got it almost maxed out, but this went fubar, swap parts, and yes I do intend to sell the leftover laptop for "parts or not working" If I can find a starter with a 1920x1200 screen

 

[QrazyQuadQore]

Yes works with display port, the monitor you can see it with a flashlight held to it btw.

 

[Jetster]

Can you explain the MS validation crapola, the Elitebook essentially uses the same parts, just the MB will be different serial numbers and such. And a different screen, chassis. Drivers shouldnt have to change or anything.

As for the other guy I already got it almost maxed out, but this went fubar, swap parts, and yes I do intend to sell the leftover laptop for "parts or not working" If I can find a starter with a 1920x1200 screen

If you change the motherboard even if its the same model your license will not be activated. It goes my the MAC address of the board.

If your external display works its not the motherboard. You have two bad monitors most likely

I don't like laptops and HP is the worst. Try taking it apart completely and put it back together. Sometimes this will fix it

 

[Aquinus]

If you change the motherboard even if its the same model your license will not be activated. It goes my the MAC address of the board.

If your external display works its not the motherboard. You have two bad monitors most likely

I don't like laptops and HP is the worst. Try taking it apart completely and put it back together. Sometimes this will fix it

I believe Microsoft's official stance is that if more than 3 "parts" in a computer change an activation will become invalid. Changing the motherboard won't always do it (I've personally done this and have been there,) but changing GPUs, memory, and drives will and you'll notice when you try to activate the computer again after re-installing (which has also happened to me.)

All in all, the laptop seems kind of useless without swapping parts. I would do it and worry about activation later.

 

[Solaris17]

you blew the fuse on the board. did you so this with the battery in? Not all screens are made equal. I literally have done hundreds over the past year. Their is a possibility the original one will no longer work as well so you may end up needing to do a board swap and buy a new screen. How did you order the new panel?

 

[QrazyQuadQore]

Had power unlpugged, no battery, when I got the new display plugged in, had a 40 pin connector was for the hp elitebook, turned it on heard a pop, burning smell, switched back to my old monitor, no backlight but with a flashlight you can see the picture on the screen.

I dont really want to take it all apart, and back together, thats hours of screws and ribbon cables and tiny doo-dads and things that fly out of the laptop and get lost. Already put a I7 M920X in it, that was fun.

So if I swapped the MB, and the screen, should work, a MB is about 100$ and a screen it 100$, OR I can get a laptop with no hdd, os, ram, or anything, and swap the parts over?? But if I get a new MB M$ activation will get fubar?

 

[OneMoar]

activation should be fine so long as its the same model/chipset has nothing todo with the MAC Address
if it presents a problem then simply bypass the activation tho usually you can just call Microsoft and explain you had to replace a motherboard
and yea it sounds like you either toasted a LVDS cable or the LVDS driver circuit as well
cable with the latter being the most likely unfortunately
http://www.ebay.ca/itm/HP-Elitebook...deo-LVDS-Cable-6017B0230901-GLP-/400709840985
board
http://www.ebay.com/itm/like/331336518797?lpid=82
if you have the skill with a soldering iron its possible to split the power off the LVDS cable and bypass the regulator and just run it at 100% all the time or install a LP8543 WLED driver someplace and splice the power to the LED in

 

[QrazyQuadQore]

I have a cable ordered from HP, so if that doesn't solve it, the circuit on the MB is probably toasted? So that chip you linked, how can I find it, to see If its burnt out on the MB and thats an IC thoes are a trick to solder, Iv done 2 20 pin IC's in a TV once before.

 

[OneMoar]

the chip I linked is not a direct replacement it would be something you would need to wire in and figure out how to use
your best bet would be another cable and simply cutting the 4 pins that power the back-light and hooking them to a 5v source on the motherboard/psu
ideally you would solder a power connection directly to the require spot on the panel and supply power that way cutting into a LVDS cable and making it work is nearly impossible
there should be a small ribbon cable on the back of the screen on the edge thats the power to the LED's you will need a multi-meter and a fairly decent knowledge of dc circuits back-light voltage vary from 3.3v to 5.0v with some even being 12.0v

honestly the easiest solution is just to replace the motherboard
there are 4 types of screens used on that model you need to match the part number EXACTLY
for that motherboard so make sure your board is a p/n identical replacement to the old screen

 

[QrazyQuadQore]

Thanks thats like the best answer yet! Exactly the techy stuff, I wanted to know.

 

[Psychovich]

I need to clarify some information about Windows 7 activation before anyone makes a costly mistake.

I worked in IT for decades and used only HP business machines at home and at work. HP does not activate windows normally, it just checks that its a HP BIOS and you're good to go. For example, I swapped a hard drive from a 8740W and put it into my 8540W and it worked fine after updating and changing a few of the drivers. It doesn't even matter what the CD key on the sticker is, as long as you have the proper restore disks. The operating system disks are interchangeable, I used a Z400 workstation desktop operating system disk with a 7000 Elite mt desktop restore disk set and it was fine.

Think about it in a business situation, I worked in a law firm where the attorney's bill at $1000 an hour, they can't have downtime. You have to be able to swap hard drives, I've even put them into newer models and had them work.

I've also taken parts from completely different models and swapped them around. Occasionally I've had to use the original model's driver, like when I put a Gobi 1000 in a 8740W.

Restore disks are crazy cheap from HP, usually in the $15-$35 range. They gave me a set of 8740W restore disks for FREE when I called them a couple of months ago. Same restore disks work perfectly on my 8540W.

I actually scored two Elitebook prototypes on eBay.

8740W ($250 with shipping)
Production model 00000001#000
Serial number CNU0123404 (its revision 4 of the motherboard I noticed) Its a junk serial number so I'm not worried about you all stealing it.
Quad Core 920xm
5000m Quadro
6300 wifi card
1900x1200 display (non-dreamcolor)
Fingerprint scanner
Added back-lit keyboard (love it - $36)
Added Gobi 2000 wwan card ($15)

8540W ($200 with shipping)
Model TPDLTEST01 (no kidding - comes up as some other computer in partsurfer on hp's site.)
Quad Core 820qm
Dreamcolor Display
6300 wifi card
fingerprint scanner, webcam and nightlight
Added a Gobi 2000 wwan card ($15)
1800 Quadro which I'm going to attemp to swap out with a Firepro 4100m which is less wattage ($34). I meant to buy the 5950m which uses the same drivers the 8540W uses (its the card for the 8560W) but they sent me one for the 8770W. I'm fairly confident it will work since they use the same video card interface. I've also noticed if you let Radeon auto detect your firepro it will detect it as the non-firepro version. Worst case I'll steal the 7820m firepro from my 8740W and cut a hole in the bottom of my 8540W and attach a huge fan system or water cooling.

I also got two base model 8740W's with firepro cards and dual cores for $225 each with shipping. I bought another quad core board ($99) to swap out.

Now I've bought a dreamcolor panel for my 8740W ($70), I'm sure I'm going to need to change cables and some other stuff to avoid your situation. Worst case, I'll steal the cables and color control board from my 8540W I read they use the same parts. Its a 50 pin cable.

I'd like to know if anyone tried putting the 8740 motherboard into the 8730 chasis, I see the screw holes don't completely line up, but the displayport looks like it lines up the the HDMI port on the 8730 and the other ports mostly match and the motherboard is the same shape.

 

[eidairaman1]

We are not dealing with business/commercial grade machines here normally but if you can get majority of holes matched up use em and remove other standoffs, Sometimes minor forcing is required to mount a board. Its normally due to the io shield tension

 

[Toothless]

Err.. Thread necro much..?

Anyway, too bad the OP had issues with switching panels. I replaced mine with a "checked compatible" panel and works just fine. All that is really needed is getting the panel that fits your exact laptop model.

As for the lack of backlights? Bad panels, just gotta replace it.