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How-to: Lenovo Laptop Dim LED Screen Backlight Fuse Repair

Screenshot of Lenovo Motherboard

screenshot of lenovo motherboard screen connector with fuse location indicated by white arrow

screenshot of lenovo motherboard screen connector with fuse location indicated by white arrow

How to identify the cause of your dead laptop screen

If you have a Lenovo laptop with a Dim Backlight, and the desktop is faint but visible this usually means that the main components of the motherboard are working fine. If you look in the photo above you can see the arrow pointing at the fuse on a lenovo laptop motherboard

However there could be a bad fuse, and in order to determine which part to troubleshoot you need to determine if you have one of two types of LCD Screens for laptops CCFL, and LED style screen, if you have the LED style screen the cause is most likely a blown fuse on the motherboard. In most cases newer laptops, are using a LED style back-light instead of CCFL‘s, which negates the need of an Inverter, so now manufacturers are placing a fuse on the motherboard, to protect the screen from surges. However sometimes a momentary problem can blow this fuse, and kill power to the screen rendering the computer unusable. however with a little time, and a lot of heat (soldering) you can replace this puppy. Identifying the proper fuse and replacing it will safe you hundreds in repair costs. when you don't want to attempt this computer repair yourself, you may be able to find a local shop that will do this type of soldering, which is still cheaper than a replacement motherboard.

If you have the CCFL Style screen (the short definition is that it is a compact fluorescent bulb). In this case it could be a bad inverter. The inverter is comparable to the ballast in your everyday shop lights, it ramps up the voltage in your laptop high enough in order to allow it to fluoresce and provide light behind the screen.

Leave me a comment if you have any questions, I have identified numerous fuses on various laptops. If your model isn't addressed here, leave a link to a High-Res photo of your board, and I'll see what I can help you find.

Comments

Roger on May 09, 2018:

Thanks... ur info is very clear and pics as well.

ben on March 16, 2018:

Ok that sound fin But your picture is not what I have (Lenovo think pad L510) the screen like all are made in China no name on it.

My screen was getting slowly darker than when it was bumped it went dark just a lltle image on it .The external plug in screen works fine

is that from the LED back lights?

kabraham@porgerajv.com on May 13, 2017:

Where will I find the screen fuse on a Lenovo motherboard? Will I still enter to BIOS if this fuse is ok? If I can go into windows using a external screen, what does that mean?

Bob on February 08, 2017:

I have a couple of X220 Tablet laptops with dim display. The content is slightly visible when you shine a torch light. Can you help to identify where lie the problem?

Roland on November 10, 2016:

Mr. Michael. can you point that fuse on motherboard of T 410 ?

If you can with bigger pic and which part of that motherboard.

Michael Reid (author) from Farmington, AR on October 17, 2016:

The steps are going to be similar to the above. If the symptoms look as if they are related to a blown fuse:

External monitor works fine. You can see icons and background with a flashlight etc.

To fix it yourself you will need to be comfortable with.

Complete safe disassembly of the laptop to remove the motherboard.

Locate and Test the Fuse that is on the circuit that provides power to the screen.

Ability to desolder and solder on a new fuse if the original one proves to be faulty.

The good news is that if this fails you are in a good position to buy a refurbished or used motherboard off of ebay, and replace the motherboard since you've already removed it.

Best of Luck

Luke purnell on October 16, 2016:

I have this issue with thinkpad x201s. Could someone please share any specific information for this model and what steps are needed in order to complete the fix?

naveedansari on April 06, 2016:

Lenovo Laptop Dim LED Screen Backlight

mada on February 05, 2016:

Hi,

Please give me a feedback to my problem .

My DIM screen is very low but still show something if I put a flashlight on it. The screen is an LCD, what could be the problem?

Thank you

Marcio Avlz on January 27, 2016:

Hi, Thank you for this nice article. This problem seems very common in this model and I would be grateful if someone would give information on where to find the fuse on the Lenovo T420 equipment. Number and any other information on how to find it. Thank you for this help!

Michael Reid (author) from Farmington, AR on November 03, 2015:

If replacing the fuse didn't work, may need to start testing the mosfet's.

remus on October 30, 2015:

hello. i have problem whit my lenovo x201, i change fuse f1, but still dont work, when I put the machine i have 20v in that fuse....can you help me pls?thx,

pcbjuan on February 06, 2015:

Hello, I have the same problem with an acer aspire one d270

Michael Reid (author) from Farmington, AR on September 26, 2014:

Ryo, yes, they are cheap and easy to source online. I apologize to those I haven't replied to, but I haven't been able to identify the fuses on other motherboards, I don't have access to a lot. I post mainly on those I have specifically fixed, or found the location of myself.

ananya on May 31, 2014:

Thank you for this info! Do you have any pointers for a thinkpad X201?

@MeM: Were you able to isolate the problematic diode or MOSFET?

Ryo on April 19, 2014:

Thanks for this. Fixed my problem with a X201i I was repairing for a friend.

The fuse is usually labeled "F1." F is obviously stands for Fuse. On mine, there was even a label under it that said "3A/35V." So replace with a same rating fuse is recommended.

PRINCE on March 27, 2014:

How to find a blown fuse in HP 650

Debra from Cowden,Il on January 08, 2014:

I have a Toshiba Satellite L305D-S5928 that has been giving me tons of trouble, first it was the heatsink and now that I replaced that the screen will not come on. I have taken the batteries out and held the power button down, and put them all back more then once and nothing happens. I have hooked it up to a desk top monitor and I don't see a thing. It has a LCD screen and I didn't understand what you said to do with them, was it replace the inverter and see if that's the problem?

Michael Reid (author) from Farmington, AR on December 08, 2013:

I don't know specifically I have not had to search for it on that model

rodka on December 04, 2013:

Hi,

do you know where is fuse for LCD on T420 motherboard? Thank you very much! :-)

Michael Reid (author) from Farmington, AR on August 04, 2013:

Don't forget to examine the Mosfet's these also can blow, are much bigger and in some cases show the problem a little easier.

MeM on July 30, 2013:

Hello, I have the same problem with an x201. I stripped this thing down to the motherboard, and I think I have checked all the fuses. Several surface mount fuses. But they all seem to be good. I can see the display is working, very dark and dim, but it's functioning. Is there any other problem I might be missing?

Thanks, if you can find the time to comment.

Uri on July 20, 2013:

Hi,

Please let us know how to find a backlight fuse on the x220.

It doesn't make sense to throw away a working computer just over a fuse.

uri on July 13, 2013:

joinning the question for x220.

Nuri form Germany on May 29, 2013:

How can i find a blow fuse , I have a Lenovo t420

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