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t460 - no lcd backlight

Posted: Mon Apr 06, 2020 2:04 pm
by jjvbjjvb
Have a T460 with mb Nm-A581. Screen is black, but flashlight shows that there is something there. Works fine when plugged into another display. There are three fuses near the LCD connector on the opposite side. F6 has a P on it. F4 has no marking and F7 has a white dot. I think F7 might be for the cooling fan. They all seem to check ok. Does anyone know which fuse is for the backlight? If the fuses are ok, what might be the problem? I'm thinking that it could either be the power supply to the backlight, a bad cable or a bad screen. Thanks.

Re: t460 - no lcd backlight

Posted: Tue Apr 07, 2020 1:26 am
by RealBlackStuff
Usually the backlight fuse has a P (for 3A, 32V, Fast) on it, like your F6.
With a multimeter set to test for Continuity, it should beep when you put the testprobes at each end of that fuse.
Do this test with charger and main batteries disconnected/removed.
Did you try to replace the LCD with batteries still in?
That will for sure blow the backlight fuse.

Re: t460 - no lcd backlight

Posted: Tue Apr 07, 2020 6:03 am
by jjvbjjvb
Thanks for the reply. The fuse tests fine with continuity setting on meter. The backlight just quit working. It's my sons laptop and it has seen a bit of abuse I'm sure. He said it was acting funny for a while before it quit. It was new in 2016. I was hoping it would be something simple.

Re: t460 - no lcd backlight

Posted: Tue Apr 07, 2020 6:16 am
by RealBlackStuff
If the backlight fuse is still OK, then try reseating the LCD-cable on both ends (with charger and main batteries disconnected/removed).
Get the illustrated HMM/manual here: https://usermanual.wiki/Lenovo/T460HmmE ... 715041.pdf
If still no luck, look for a replacement screen, preferably FHD.

Re: t460 - no lcd backlight

Posted: Tue Apr 07, 2020 9:05 am
by jjvbjjvb
Thank you for your help. I will give it a try.

Re: t460 - no lcd backlight

Posted: Sat Apr 11, 2020 12:53 pm
by jjvbjjvb
Re-seated the connectors, same result. Any suggestions for a good source for a replacement screen? A lot of them pop up and I'm sure some sources are better than others. This is one that I found. https://www.laptopscreen.com/English/mo ... %20SERIES/

Found another for $29. Guess you can't know until you try.

Yes, I'd love to have a Guinness sitting in front of me right now.

Re: t460 - no lcd backlight

Posted: Sun Apr 12, 2020 1:14 am
by RealBlackStuff
The consensus seems to be that AUO B140HAN01.3 is the best screen for that model, followed by LGD LP140WF3-SPD1.
Either one will work OOTB.
Ask Laptopscreen (or others) if they have the REAL above AUO or LGD, and NOT a "compatible".

Re: t460 - no lcd backlight

Posted: Sun Apr 12, 2020 8:30 am
by jjvbjjvb
Thanks again.

Re: t460 - no lcd backlight

Posted: Wed Apr 15, 2020 10:51 am
by jjvbjjvb
I installed a new LCD. Now, I see nothing, not even with a flashlight. Is it possible that the t460 does not support FHD? I did see some discussions that FHD may not be supported unless you have the proper cable. Does that mean that the LCD will not light up at all, or that the higher resolution is not supported?

Re: t460 - no lcd backlight

Posted: Thu Apr 16, 2020 1:34 pm
by jjvbjjvb
OK, All is well. Apparently it didn't like that I had a second screen attached via hdmi. Unplugged it and had a nice brigh Lenovo on the screen. The screen looks much better than the original. I got it from laptopscreen.com. Thanks again for all of your assistance.