Vaio 17.3 LED Displays only white! Please help!

Hi everyone. I'm desperate for help. I have a Sony Vaio PCG-71511L. There's not alot of information I can find when using that model number so going off the model number on the bottom right of the screen, it's a VPCEF22FX. Initially the screen was displaying a distorted image, when I took the laptop apart I think I probably messed up and perhaps shorted a fuse because the LED is now displaying only in white. Externally, everything displays perfectly fine (via HDMI port) and the computer boots to Windows with no problems. I just tried out another set of cables (hoping it would be a quick fix), but the cable is not the problem. So, now I'm down to two options. Either the LED screen is broken? Was the distortion the first signs of an LED screen giving out? or perhaps there's a blown fuse somewhere on the motherboard?

Now I was desperate for an answer when I tried this so please dont judge me, but I tried this LED screen on my HP laptop and the display turned on. The difference however is that on the HP it only displayed in black. In all scenarios I explain, the backlights are on. I then went ahead and tried my HP LED screen on the Sony and there was nothing. No backlight either.

I'm scared that if I buy a new screen that it wont solve the problem since the back lights work and it displays in both black and white. This is why I'm leaning towards the possibility that it may be a fuse problem. I'll upload a picture of the motherboard if anyone can help point me in the direction of the fuses I should check.

Any help is appreciated. I was reading everyone's response on the no backlight thread and everyone seems extremely knowledgeable. Thanks again in advance.

 

Yeah, Sony uses a slightly different screen than other manufactures in my experiences. Did you make sure to have both laptops powered off, battery pulled and unplugged from the the outlet before removing and changing screens? Cause you could have blown the back-light fuse on the Sony mother board if you hadn't, that could explain why you got no back-light on the HP screen!!! But then again Sony uses different pin assignments on the LVDS screen connector cable so that might be why? Does the HP screen work on the HP laptop now???

I'm leaning towards a bad screen on the Sony laptop. Please make sure that the back-light fuse on the motherboard is not blown either, with a multimeter. Also It's possible that there might be a blown fuse on the circuit board on the back of your LED screen, check that too. I believe there was another guy with a similar problem who had a dud 17.3" on his Vaio as well and the screen turned out to be a Chinese screen and not a higher quality screen as in most Vaios, which use LG and sometimes Samsung.

 

How careful were you with the cable between the display and the motherboard? When I changed my screen I had a difficult time with that because of my poor eyesight. There are a bunch of wires in that tiny cable; very easy to break something. On my laptop model, that cable passes through the hinge, and if you're not careful in dressing the cable, the hinge can pinch the cable and damage it.

 

Thank you so much for trying to help me. I'll answer your questions to the best of my ability below.

Yeah, Sony uses a slightly different screen than other manufactures in my experiences. Did you make sure to have both laptops powered off, battery pulled and unplugged from the the outlet before removing and changing screens?

[Yes, but regarding the first attempt with the Vaio alone I may have let the LED connector cable touch the motherboard as I was attempting to test whether uncramping the cable would help. During this time, my idiot self had it plugged in.]

Cause you could have blown the back-light fuse on the Sony mother board if you hadn't, that could explain why you got no back-light on the HP screen!!! But then again Sony uses different pin assignments on the LVDS screen connector cable so that might be why? Does the HP screen work on the HP laptop now???

[I was hoping it was a back light fuse but now it's looking more uncertain because when I plug the original LED screen back in, poof, all white. Quite crystally clear might I add. And yes, luckily I did not mess up my HP and it's working fine. I'm guessing that logically, the HP screen did not work on the Sony due to incompatible connectivity. But would you happen to know why the screen would power on with back light but in black on the HP? This was really the only indicator that threw me towards the possibility that the screen is okay.]

I'm leaning towards a bad screen on the Sony laptop. Please make sure that the back-light fuse on the motherboard is not blown either, with a multimeter.

Yes, I will give that a try. If it's a screen problem I really can't afford to fix it. I'm just a college student who has to try to deal with these things because I refused to take out student loans. But the least I can do is properly diagnose the problem so I can sell it honestly to someone. (I dont want to say motherboard fuse when it's the screen and vice versa).

Also It's possible that there might be a blown fuse on the circuit board on the back of your LED screen, check that too. I believe there was another guy with a similar problem who had a dud 17.3" on his Vaio as well and the screen turned out to be a Chinese screen and not a higher quality screen as in most Vaios, which use LG and sometimes Samsung.

[This sounds like a possibility as well. It seems as if the board on the back of the LED is making a rather unusually louder buzzing noise. Does that sound like an indicator of a fuse problem on the LED circuit board? Initially, the images on the screen were there, just very distorted and blurry which lead me to believe it was a connectivity issue. It went white after the connector wire touched the motherboard during testing as it was plugged in. You're right, it's a chinese LED. Wow, I didn't know FRY's were such crooks.]

I will upload pictures of the circuit board and motherboard. Can you help point me in the right direction? You have been extremely helpful and I am truely appreciative.

 

Hi anytimer! I just ruled out the possibility of it being the cable because I just tried a new set I ordered and it does the exact same thing. Thank you for trying to help me for I am truely appreciative.

 

Ok make sure the backlight fuse is not blown on the motherboard and order a new screen from a reputable place such as Screen for Sony VAIO VPC-EF22FX. Replacement Laptop LCD Screens I have used them in the past and they are very knowledegable and helpful as well as excellent warranty. They also sent me the original S. Korea made LG screen that Sony put in the laptop and not a cheap replacement or not even the LG branded replacement screen. I know there screens tend to be a few bucks more expensive than others but you get quality. Please make sure you select the correct one, glossy or matte and you can even ask them the make of the screen they'll send out to you.

Good Luck

 

When you get around to posting pictures, add one with the 'black' display you get with the screen connected to the HP. I don't understand what you mean. Are the desktop icons visible, but in black and white - no colour? Or is the backlight off, so the screen is really dark, but you can still make out the desktop icons if you look very carefully?

I would like to be able to figure out if the LCD controller on the screen is still alive or totally fried. The white screen you see when you connect the screen to the VAIO is LED backlight only - no display controller activity. That suggests to me that the controller is not driving the LCD at all, which points to a hardware fault in the screen itself - either the controller, or the power supply being fed to the controller.

The odds are good that a new screen will work. If you can borrow one for testing, great. Otherwise you'll have to flog it on eBay if the new screen doesn't work.

 

Thanks for responding again anytime and I apologize for my lack of clarity. I was curious to see whether the Vaio LED displaying white would work on my HP laptop. When I plugged it in to the HP, the backlights turned on, but instead of displaying all white like it did on the Vaio, the display was black with the backlights on. Next I wanted to see if the HP LED would work on the Sony but it didnt even power up at all (no backlight, no display). Put the HP back into the HP and its working fine. Put the original Vaio screen back into the Vaio and again white with backlight on. The only conclusion I can definitively draw from this test is that connectivity compatibility issues prevented the HP LED from working on the Sony. And perhaps the same compatibility issues powered the screen with a black display on the HP?

I think you're right about the controller being fried. The screen makes a buzzing noise when it's displaying in all white like it's lacking power and doing something to make up for it. But the screen does not dim and does not seem to be effected in anyway. I found out its a cheap LED screen from China. Obviously I'm a fool, and we need to be cautious when walking around stores like Fry's and Best Buy and we see a sale. Sales nowadays could mean they switched your original parts out for cheap chinese replicas that are timed to give out just after the warranty expires (or manufactured it this way). Sad that my small ebay business (I dont believe in student loans) putting me through college is more ethical yet they're the ones that make all the money. But regardless, I'm not here to complain.

I would take a picture of the black display on the HP but I already put that laptop together and am using it as of right now. If you feel it's necessary, ill take it apart again and take photos. Regarding photos for the Vaio, I'm just waiting on a DSLR so the pictures can be as clear and undraining on the human eye as possible.

Does the screen displaying black with the backlight on directly contradict what constitues as a broken LED?

Also, is it safe to assume the fuses on the motherboard are okay since the backlight is still on? And if it is a controller problem, is the only solution to get a new screen?

This is by far the best forum I have found on the internet. You guys are totally awesome!

 

No need for the picture - your explanation is good enough. The LCD is totally blank - all white when connected to the VAIO, all black when connected to the HP.

If you are into electronics (or have a friend who is), try measuring supply voltages on the controller. If the power converter for the controller supply is giving incorrect voltages, the controller might not be able to read the display data sent from the motherboard (the logic detection levels are power supply voltage dependent). Google for the part number printed on the controller chip and see if you can find out what voltages it needs, and compare with what it is getting.

Most people would simply buy a new screen, but I'm from India and am all too familiar with limited financial resources. If all attempts to fix it fail and you have to buy a new one, shop around for the best deals. This is where I got mine: SONY Z Series B131RW02 V0 Laptop Screen and they were cheaper than everyone else by a fair margin.