Thinkpad T420 and some problems with the Display

Hi everyone, I've got this Thinkpad T420 since february '15, and this last week, a small dotted line appeared on the lcd display:

The line appear also in the BIOS, and I plugged another monitor to the laptop, and there wasnt a dotted line in it, so I'm pretty sure its a hardware problem, and not a driver/software one. So my questions are:
1)Should I change the LCD panel?
2)Do I also need to change the flex cable?
3)Which panels are compatible with the T420?
4)Can I use a LED panel, instead of an LCD one?

I think thats it for now, thanks in advance for your answers

 

1. probably, but first I would open it up and reseat video connector,
2. probably not, unless it's broken. changing cable could be much more involved than replacing screen.
3. get HWinfo, write down monitor code it will show, go to web site selling LCD screens and look for compatible screen replacement. if you want exact same screen, call them to confirm, chances are they will send you cheapest compatible screen that will fit your computer
4. I don't think so

 

That's a row of dead pixels.

Yes.

No.

Download HMM from here and make sure to get a *genuine* Lenovo panel with a FRU number, and not a "compatible" one...

http://support.lenovo.com/us/en/pro...s/thinkpad-t-series-laptops/thinkpad-t420?c=1

T420 already sports a LED screen. CCFL was never an option on these machines.

Good luck.

 

Thank you for your answers

1) Are you refering to the panel connector or the motherboard connector?

What is HMM? Sorry I'm not seeing it in the link above

 

Sorry for jumping ahead of ajkula66, HMM = Hardware Maintenance Manual. The link is below:

https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/t420_t420i_hmm.pdf

Good luck,
John

 

Ah, thank you
I've found a display compatible with the one I have
http://articulo.mercadolibre.com.ar...y-b140xw03-v0-led-140-pulg-wxga-hd-brilla-_JM
Could this work? Keep in mind that I can't use sites like amazon or ebay, so this may be my only option

 

Not knowing where you reside, I can't make heads or tails of the actual price for that screen and the fact that I don't speak Spanish is not helping either...

Can you provide some guidance here?

 

ajkula, I'm very sorry I took so long to answer your question, I was busy with study stuff. So here I'll try to explain:
I run a test with HWInfo, as pete962 suggested, and this is then result for the Display:

As I remarqued, the Monitor name is B140XW03 V1. So I looked for that sort of display in that page, and I found the link I gave to you.
Now in the link they sell a B140XW03 V0, but it said that is compatible with the V1 models, so I thought I shouldn't be any problem. Dont worry about the price, as it is in the expected range.
Is it anything else I should be looking for?

Thanks in advance

 

Locate the specsheets for each panel and compare pinouts. That's the key for not blowing a fuse on the motherboard.

Good luck.

 

You could get away with the V0 panel without major issues, I'm running a Non-Lenovo glossy panel (AUO B140RW02 V0) on my T420 and it works absolutely fine so I be very surprised if the panel with the right LVDS pins don't work on yours.

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Despite what DPMS says the screen does go to sleep when inactive, powers off when required and follows brightness controls using the FN keys as you would expect. I don't see any difference in performance when compared to the original panel (apart from being glossy obviously).