No Backlight on LED screen

@d1973z28, your laptop model has been shown in this thread many times.
Anyway, F16 is the right one you need to replace or bridge it.

 

Hello,

When you say bridge a connection, does this mean solder over the fuse from connection to connection?

 

Yes it is.

 

(Finally) got my motherboard out.

I've uploaded a picture. Is it F16 I need to bridge? It appears to have popped off completely!

 

Your laptop doesn't have F16 fuse. It is NOT to have been popped off.
For this reason, I doubt your laptop came with LED LCD.
How many connectors do you have with LCD cable?

 

Sorry, but LCD cable? do you mean to the screen? It's just 1 cable. 40 pin connector.

Also the screen inside the laptop is a LG 17.3" LP173WF1 TL C1 (Full HD) LED?

 

If you have just one connector (40pins), then check F15 as I circled in below photo.

 

Hi, can someone help with identifying where I need to solder

Here are links to photos:

ImageShack® - Online Photo and Video Hosting
ImageShack® - Online Photo and Video Hosting

thanks

is it the F17 I need to solder?

 

F17 could be the one because its rating at 3A.
However, I don't know if you need to solder it because I don't know if it is blown or not.
You should check it first.

 

​

​

how do I check and if its not that, which other fuse could it be?

 

It was F17, now working!

Thanks a lot, you have saved me from a right mess!

 

Hello Dear

I have same problem with my sony vaio pcg 71881m, when turning on, it's working but with very dark screen, I checked F4 it was ok.
can you help me?

 

Thank you very much ngvuanh

I have Sony SV-S 15 (bought in April 2013). I can confirm that Series S15 motherboard is same as m_ugur 's S13. I weld the fuse circled in yellow and it works.
PS : You do not need to take out the motherboard. the fuse located just below screen cable connector.

 

Please help. Going mad
Same problem.
Vaio vgn bz21vn or pcg9z1m
Welcome to Flickr!
Welcome to Flickr!
Bottle of single malt to anyone that can help!

 

@ijmunro69
The fuse is marked as L13 close to LCD connector.
L is supposed to be an inductor coin, but I notice it is a fuse actually.

 

Legend! I have no idea how many hours i spent looking for that wee green fuse or a component marked with an F!!!
Thank you. [email protected] send me your address off forum and i'll send you a bottle!

 

I have the same problem with the pcg61a11u, mbx250 board, appreciate your help, which is not the fuse

 

Check fuse F4901. It is close to network jack.

Sent from my C6606 using Tapatalk 4 Beta

 

Hi ngvuanh...I can see that you are some kind of tech wiz as far as this particular problem goes. I have just had my pc back (still not working) after paying good money for someone to tell me I need to change the video cable to rule that out, etc. Reading this thread, I have exactly the same problem..I replaced my screen (as I cracked the original) and the new one was working but with no backlight. I thought it was faulty so sent it back and the next one had the same problem. Out of curioisty, I put my old screen back on and found that was no longer working either, so pointing to a different problem. The PC is booting up and I can vaguely see my desktop, which kind of points to the 'blown fuse' issue that most people have experienced on here.

Well,I have just been and bought a soldering iron and would love to know, what part of the motherboard contains the affected fuse for my model;

I have a SONY VAIO
MODEL PCG-71911M
Product Name VPCEH3N6E

Really hope that you can help me!!

Thanks
Andy

 

The fuse is F4 which is close to LCD and Power connectors.

 

Ngvuanh Hello, I'm months without the notebook because of this problem, now I see a light, could you help me please?

My notebook is Sony VAIO VPCF226FM (Model PCG-81311L)

Pictures:



Thank you!

Jose

 

I need a picture of other side underneath LCD connector.
Please use high-res and close up.

 

Hi, ngvuanh,
I posted more photos ..
thank you very much

 

I'm trying to find a fuse but I want to ask you more.
Do you know that if your laptop has led lcd or regular lcd?
How many connector do you see at the end of lcd cable?
I found 3 fuses in the area but 2 of them are not populated.

Sent from my LT30at using Tapatalk 4

 

Hi ,

After replacing the cracked screen on my S ony notebook SVE1512E6EW the backlight doesn't seem to work. I put back in the old screen and backlight no longer seems to be working on that screen either. I have read that this might be related to a blown fuse on the motherboard. I was hoping someone could help me locate the fuse on the motherboard. I don't know where to start looking .

I have attached some pictures that might help.

 

Hello ngvuanh, once again thank you.

Do you know if your laptop has que led lcd or regular lcd?
Led lcd
How many do you see connector at the end of lcd cable?
Two (see image)

 

The second answer told me your laptop has CCFL backlight because LED backlight doesn't use separate power supply (small connector).
You should double check by opening LCD panel.

Sent from my SGP311 using Tapatalk 4

 

See post 149 in this thread, you will find my answer.


Sent from my SGP311 using Tapatalk 4

 

As I understand it the second connector is the webcam (see image)

 

I found it, the fuse F29.

 

Hello ngvuanh,
Thanks for your quick response.
I was able to locate Fuse F4 and able to take some photos. if I compare with picture in post 149 the fuse on my laptop looks to be in better condition? Is there anything that you can make out from the pictures?

Is there an easy way to test? I'm not a technical person so any detailed instructions that you could provide would be very much appreciated !!!!
Thank you once again !

 

To test the fuse, you can find a metal paper clip, bend it to have 2 end points next together.
Touch 2 end points of that clip to 2 end points of the fuse while the screen is on, if you see back light on, then the fuse is gone.
Be careful not to touch to other small parts.

 

I tested with paper clip; nothing happened and suddenly the laptop powered off. I hope I didn't blow another fuse with this action .
After a few minutes I was able to start the laptop normally. I connected the laptop with an external monitor and was able to logon to windows and see everything.

I tested with a multimeter as well but there were no readings; nothing changed on the display. Not sure though if I performed this test correctly.

 

If you tested with multimeter and saw no reading, then the fuse is gone.
Bridge the fuse and your laptop should work again.

Sent from my Sony Tablet S using Tapatalk 2

 

Hello,

ngvuanh i read most of the answers and as i can see all the laptops are different i cannot see any "N" Fuse... mine next to the LED connector is a "H" fuse, like the one in the picture...

Is this H fuse the one to bridge?

Thank you in advance, your doing an awesome help to a lot of people.

 

And do i have to take the Fuse off and bridge or i can bridge over it?

Thank you!

 

@Milknotebook, you have the fuse with H mark. You don't need to remove the fuse, but it will make you easier to bridge with fuse removed.

 

Ngvuanh, as I posted in my thread I bridged the fuse and I still don't have backlight with the brand new screen as well.

 

You should get a cheap voltmeter to measure the fuse.
Make sure you have both ends read at 19.5V.
If you have voltage at only one end, fuse need to bridge or re-bridge.
If you have no voltage at all, it's different issue.

 

I am going to try bridging it again. I tested for continuity of the bridge and it tests ok at the top and accross the bridge but on one end of the bridge close to the motherboard (on one footing end to end), I am not getting continuity. So I'll remove the bridge, this time remove the fuse and try it again.

 

You don't need a soldering iron to remove the fuse. You can use a small tips tweezer to remove it.
Just hold to its side and wiggle it, it will come out.
Then you want soldering iron to do the rest.

 

SUCCESS!
Thanks ngvuanh!

 

I have a Sony Vaio sve151j13l with the same exact problem.. just wondering if anyone has had the same problem with this model before I take it apart and will I need to take the whole laptop apart? thank you

 

LED backlight problem could be a blown fuse or other problems.
The first step you should do is open back cover and measure the fuse or try to bridge it if you don't have multimeter.
The fuse is located in the corner of LCD and power connectors. I circled it red in attached picture.

 

Hi everyone, I have the same problem with my Acer TravelMate 8372Z, tried to bridge Fuse F1 but no luck, i think it is Fuse F2 (011 P), what do you say ngvuanh !!!! View attachment 101935 View attachment 101936
Note: when i tried to bridge F1 my acer doesn't turn on until i removed the bridge but no led backlight of course.

 

WGenius, F1 is the right one. However, if you bridge it and your laptop won't turn on, then there may be a short circuit.
I would suggest you to do as follow to find the actual issue.
Bridge F1, turn on the laptop with LCD cable unplugged. If your laptop can turn on, then LCD controller board is shorted. Otherwise, the circuit from F1 to LCD connector is shorted.
Let me know this outcome first.

 

Got it :thumbsup:

 

I did bridge it again (F1 Fuse) and now it works, led backlight is back (Strange; the first time didn't work), but i have a question ngvuanh : that bridge trick have any future damages (probably yes then what is the role of that fuse) !!!! if yes what kind of damages !!! in order to change that fuse do i have to look for Fuse with N type !! example of capacitors : for a capacitor with (10v 1000µ) we look for 10v 1000µ or greater (µ), and for Fuse !!!!! and if it measured by type or by rate (A), if by rate how to measure its rating !!! can i look for type N in another laptop !!!! thanks in advance for the great help and the time you spend for us.

 

LED array is powered by power supply over the fuse, then the fuse is to protect the LCD controller board (LED circuit) from damage if there is a power surge. But actually, there is also another fuse on LCD controller board to protect them. So LED array is protected by 2 fuses in serial connection. If one failed, it cuts the power off.
In this situation, bridging external fuse is still safe because of the fuse on LCD.

Sent from my SGP311 using Tapatalk 4

 

Thank you so much for your explanation, what about rate measurement ! is it by type or by (amp) ! if by amp how to measure it !! thank you in advance. all the best! :hi2: