Take a look at our
ThinkPads.com HOME PAGE
For those who might want to contribute to the blog, start here: Editors Alley Topic
Then contact Bill with a Private Message

Keyboard stubbornly not backlighting

T430-T490, T530-T590 Series
Post Reply
Message
Author
Lijsterbes
Posts: 3
Joined: Sat Oct 15, 2022 5:00 pm
Location: The Hague, the Netherlands

Keyboard stubbornly not backlighting

#1 Post by Lijsterbes » Sat Oct 15, 2022 5:26 pm

I bought a refurb T540p, cheap but refurbed by a drunk baboon. I replaced HD, screen and RAM, all to full satisfaction, and now I swapped out the worn-out and cracked non-backlit keyboard for a shiny new Lenovo branded backlit keyboard.

The backlight, however, doesn't light up. At any time. Not in normal operation, not in the firmware setup, no flickers of light during POST, nothing. The kernel [I run linux] exposes some backlight /sys/ files, so the kernel recognizes that it's there, but writing to them doesn't make my backlight do anything. I tried everything short of updating BIOS [my experiences updating BIOS are a mixed bag at best, and the changelogs both mention nothing about keyboard or backlight fixes, AND explicitly state that rolling back updates is blocked [I'm at BIOS 2.33 anyway, current version would be 2.39 - nothing but 'security patches' in between]]; I tried all software fixes I could find, I've reseated the cables multiple times, I've power cycled the machine multiple times, nothing. I've even gone so far as installing Windows to see if that would help, but no dice. The keyboard functions normally, the Fn led and F1 led function fine, but no backlight!

I'd be greatly helped with any of the following:
1) The Silver Bullet Solution that will get this thing to work
2) What hardware issues I might be overlooking, and how to diagnose them
3) How to identify whether or not the keyboard itself is defective, and should get RMA'd.

RealBlackStuff
Admin Emeritus
Admin Emeritus
Posts: 23809
Joined: Mon Sep 18, 2006 5:17 am
Location: Loch Garman, Éire

Re: Keyboard stubbornly not backlighting

#2 Post by RealBlackStuff » Sun Oct 16, 2022 12:01 am

What is the P/N or FRU from that keyboard?
Is there a light-symbol (shining away from you) on the spacebar?
Have you tried Fn+Spacebar? (Backlight Off/Low/High)
Lovely day for a Guinness! (The Real Black Stuff)
Lenovo: X240, X250, T440p, T480, M900 Tiny.

PS: the old Boardroom website is still available on the Wayback Machine
.

Lijsterbes
Posts: 3
Joined: Sat Oct 15, 2022 5:00 pm
Location: The Hague, the Netherlands

Re: Keyboard stubbornly not backlighting

#3 Post by Lijsterbes » Sun Oct 16, 2022 4:57 am

I don't know how to ascertain the FRU or P/N of the keyboard. According to the seller, its part number is 04Y2387, 04Y2465, 0C44592, 0C45030, 04Y2387. It is sold as original Lenovo branded.

There is the light-shining-upward symbol on the left side of the space bar.

Pressing Fn + spacebar does nothing. Not in my Linux DE, not in BIOS, not in Windows, not in BartPE.

RealBlackStuff
Admin Emeritus
Admin Emeritus
Posts: 23809
Joined: Mon Sep 18, 2006 5:17 am
Location: Loch Garman, Éire

Re: Keyboard stubbornly not backlighting

#4 Post by RealBlackStuff » Sun Oct 16, 2022 5:34 am

04Y2387/0C44592 = backlit Chicony US
04Y2465/0C45030 = backlit LiteOn US

Most likely your KB is a Chinese knock-off of unknown origin.
Is the back fully covered with a black plastic sheet? As seen e.g. here: https://www.ebay.ie/itm/113157401121
If not, it's not backlit. As seen e.g. here: https://www.ebay.ie/itm/373677219339
If yes, it's either defective or part of the knock-off procedure.
Either way, if bought on eBay, open a case "not as described" or "faulty", then return for a refund.
Lovely day for a Guinness! (The Real Black Stuff)
Lenovo: X240, X250, T440p, T480, M900 Tiny.

PS: the old Boardroom website is still available on the Wayback Machine
.

Lijsterbes
Posts: 3
Joined: Sat Oct 15, 2022 5:00 pm
Location: The Hague, the Netherlands

Re: Keyboard stubbornly not backlighting

#5 Post by Lijsterbes » Sun Oct 16, 2022 10:58 am

The keyboard is NOT covered with a black sheet on the back. The backside is a white panel, but the connector ribbon cables look similar to the original you linked to.

Is there any way I can prove that the part is defective, and it's not due to my machine?

ZaZ
Moderator
Moderator
Posts: 4698
Joined: Fri May 13, 2005 1:33 pm
Location: Minnesota

Re: Keyboard stubbornly not backlighting

#6 Post by ZaZ » Sun Oct 16, 2022 11:23 am

Is the part number not printed on the back? I'd just ask the seller for a replacement or return.
ThinkPad L14 - 2.1GHz Ryzen 4650U | 16GB | 256GB | 14" FHD | Win11P
ProBook 470 G5 - 1.6GHz Core i5 | 16GB | 2.2TB | 17" FHD | Mint

Post Reply
  • Similar Topics
    Replies
    Views
    Last post

Return to “ThinkPad T430-T490 / T530-T590 Series”

Who is online

Users browsing this forum: No registered users and 29 guests