Thinkpads Forum

Hey there,

I blew my T480s backlight fuse on trying a WQHD upgrade (yeah I'm an idiot...)

Could anyone show me a picture or give hints about the fuse location?
Do I need to take the whole motherboard out of the case or can I check the fuse leaving the board where it is?

Thank you.

sandreas

I'm going to be as helpful as I possibly can, because I'm also trying to figure this out on my T480s. Please keep in mind: I am waste.

I was able to find a free schematic here, but I'm still stoopid in finding what the backlight fuse would be. I believe it's required to get a 32V 3A fuse for the backlight, which could prove helpful to find the fuse.

Additionally, it seems as though the fuse itself isn't accessible, but bridging another fuse over the other one is a preferable solution on other Lenovo boards. (I cannot speak to how effective this would be on the T480s.)

I want to complete this repair on my board, and I will make an effort to reply to this post, or make a new post and reply with a link to it here.

Any other info any other readers would like to provide me, would be much appreciated! Then, I can make a detailed tutorial, and people could just link to that instead of these half helpful links to irrelevant boards.

Peace and love,
waste

sandreas wrote: ↑

Thu Sep 30, 2021 2:12 pm

Hey there,

I blew my T480s backlight fuse on trying a WQHD upgrade (yeah I'm an idiot...)

Could anyone show me a picture or give hints about the fuse location?
Do I need to take the whole motherboard out of the case or can I check the fuse leaving the board where it is?

Thank you.

sandreas

How did you blow it?
I'm waiting for a 4K screen to fit into my T480 FHD touch screen.
I know there is 40pin cable in mine, but I read that the touch screen 40pin cable is not the same as QHD (and 4K) 40pin cable.
Not sure if in case it's true, the 4K screen will just not work, or will it blow up a fuse on mobo.

Blacklight fuse should be next to video calls connector on the motherboard. Marked F3 or J3, I'm truly not expert. Hopefully RBS will come in, he knows the subject.

On T480 schematics it's fuse F3 on page 26, above the LCD-connector.
On T480s schematics it's fuse F2 on page 26, above the LCD-connector.
Both are marked: 3A_32V_ERBRD3R00X
They are 3A/32V/Fast.
Piggyback solder a new one on top of the old one.
NOTE: Those fuses are on the bottom of the mobo, roughly underneath the LCD-connector.

@Natakranta:
The T480 has standard 40-pin eDP LCD-cable 01YR501.
Touch needs LCD-cable 01YR502.
WQHD needs LCD-cable 01YR503.

WQHD probably also needs a different lid and/or LCD-bezel from Touch.
Have a look here: https://libthinkpad.github.io/fru/

Natakranta wrote: ↑

Mon Nov 08, 2021 7:09 pm

sandreas wrote: ↑

Thu Sep 30, 2021 2:12 pm

Hey there,

I blew my T480s backlight fuse on trying a WQHD upgrade (yeah I'm an idiot...)

Could anyone show me a picture or give hints about the fuse location?
Do I need to take the whole motherboard out of the case or can I check the fuse leaving the board where it is?

Thank you.

sandreas

How did you blow it?
I'm waiting for a 4K screen to fit into my T480 FHD touch screen.
I know there is 40pin cable in mine, but I read that the touch screen 40pin cable is not the same as QHD (and 4K) 40pin cable.
Not sure if in case it's true, the 4K screen will just not work, or will it blow up a fuse on mobo.

Blacklight fuse should be next to video calls connector on the motherboard. Marked F3 or J3, I'm truly not expert. Hopefully RBS will come in, he knows the subject.

Don't use the touch cable for the qhd/uhd panels you will destroy the panel

RealBlackStuff wrote: ↑

Tue Nov 09, 2021 1:24 am

@Natakranta:
The T480 has standard 40-pin eDP LCD-cable 01YR501.
Touch needs LCD-cable 01YR502.
WQHD needs LCD-cable 01YR503.

WQHD probably also needs a different lid and/or LCD-bezel from Touch.
Have a look here: https://libthinkpad.github.io/fru/

Thanks RBS! You are truly the Encyclopedia Magnifica!
I'll buy 01YR503 for the 4K display panel I bought.
I try to fit it into current lid, set of modeling files, a dremel and my artistic sculpting skill will have to do

iamdmc wrote: ↑

Tue Nov 09, 2021 5:05 am

Natakranta wrote: ↑

Mon Nov 08, 2021 7:09 pm

How did you blow it?
I'm waiting for a 4K screen to fit into my T480 FHD touch screen.
I know there is 40pin cable in mine, but I read that the touch screen 40pin cable is not the same as QHD (and 4K) 40pin cable.
Not sure if in case it's true, the 4K screen will just not work, or will it blow up a fuse on mobo.

Blacklight fuse should be next to video calls connector on the motherboard. Marked F3 or J3, I'm truly not expert. Hopefully RBS will come in, he knows the subject.

Don't use the touch cable for the qhd/uhd panels you will destroy the panel

Thank you iamdmc! This is the information I was looking for, a verified confirmation that it not only will not work, but will actually destroy something in a process. I was more cautious about the motherboard, but frying new 4K display is bad as well.
So as RBS advised, I have just ordered 01YR503 and need to wait a month for it.

The eDP cable I ordere form China came surprisingly quickly and last night I did some testing with the 4K screen I bought form eBay Germany.
A teaser for now, proper thread with more pictures and full story to follow after I finish placing the panel in T480 lid.

Natakranta wrote: ↑

Sat Nov 20, 2021 1:53 pm

The eDP cable I ordere form China came surprisingly quickly and last night I did some testing with the 4K screen I bought form eBay Germany.
A teaser for now, proper thread with more pictures and full story to follow after I finish placing the panel in T480 lid.

congrats!

which panel did you go for?

iamdmc wrote: ↑

Sun Nov 21, 2021 5:55 am

Natakranta wrote: ↑

Sat Nov 20, 2021 1:53 pm

The eDP cable I ordere form China came surprisingly quickly and last night I did some testing with the 4K screen I bought form eBay Germany.
A teaser for now, proper thread with more pictures and full story to follow after I finish placing the panel in T480 lid.

congrats!

which panel did you go for?

I bought this one from this seller DCI-P3 90% 4K UHD NV140QUM-N53 BOE07C8 IPS. Very bright and lovely colours, only drawback it is glossy, but I'm used to as I have a glossy 14" on my work laptop for over 2 years now.

All work is done, I just need time to write post with good descriptions and links to pictures.

Does anyone know what to do if the fuse is fine but the backlight doesn't work? I was told that it might be what supplies power to the fuse but I don't know what does.

Faulty LCD comes to mind...