Thinkpads Forum

Would this remark on the AUO Datasheet help?

Note 2 : If the PWM duty ratio(min) is set between 5% to 1%，the PWM input frequency should be set below
1KHz . The brightness-duty characteristic might not be able to keep in it’s linearity if the dimming control is
operated in 1% to 5% range.

On most screens there is also a fuse on the LED-panel, probably hidden under the DO NOT TOUCH stuff.
Did you also check the fuses F3 and F4 near the LCD-connector?

RealBlackStuff wrote:Would this remark on the AUO Datasheet help?

Note 2 : If the PWM duty ratio(min) is set between 5% to 1%，the PWM input frequency should be set below
1KHz . The brightness-duty characteristic might not be able to keep in it’s linearity if the dimming control is
operated in 1% to 5% range.

On most screens there is also a fuse on the LED-panel, probably hidden under the DO NOT TOUCH stuff.
Did you also check the fuses F3 and F4 near the LCD-connector?

The problem is not in the backlight circuit itself. BIOS can't use dual monitor configuration, thus there's no backlight enable and dim signals for default built-in LCD.

Also, how much soldering is needed? it seems like just two wires need to be soldered in, seems easy enough.

I hope it would require only 8-9 soldering points, all on docking port connector pads. Like here (see round pads on top of the red board):
http://img-cdn.jg.jugem.jp/156/3028867/ ... 182065.jpg

Are you talking X220 or X230?

RealBlackStuff wrote:Are you talking X220 or X230?

Both. They have same pinout of LCD and docking connectors, so the adapter would work with both models.

Another update: new prototype supports brightness control. So, basically, it's gonna be a replacement for chinese mod kit. Hope to get a production version soon.

nitrocaster wrote:So, basically, it's gonna be a replacement for chinese mod kit. Hope to get a production version soon

Nice!

Just uploaded a short (and pretty crappy, huh) demo on YouTube: https://youtu.be/SKb6llRurLQ

Cool, I'm really looking forward to this mod. I love the X2x0 machines, but that 1366x768 resolution... Oh boy...

I need this......

wabamad wrote:I need this......

No party for tablets. At least, in the first batch and until I get one of these.

I would get a non tablet to have a fhd screen.

nitrocaster wrote:Another update: new prototype supports brightness control.

Cool! How did you make brightness control work?
And what do you expect your kit to cost, if you get into production?

Backlight control is provided by LVDS output. The problem with the previous prototype was that backlight either didn't work in bios or was enabled all the time. Now it's fixed at 100% level in BIOS and works as expected in Windows. BIOS mod is required to disable LVDS output so that it would be single display mode instead of duplication mode.
I suppose the price would be around 60 bucks. Don't know shipping costs yet.

nitrocaster wrote:Backlight control is provided by LVDS output. The problem with the previous prototype was that backlight either didn't work in bios or was enabled all the time. Now it's fixed at 100% level in BIOS and works as expected in Windows. BIOS mod is required to disable LVDS output so that it would be single display mode instead of duplication mode.
I suppose the price would be around 60 bucks. Don't know shipping costs yet.

I hope this will work with X230, any insight?

thank you!

Yeah, it's compatible with X220/X230. Final PCB design is ready for production.

Just a quick question, because I'm sure you are familiar with the PCB layout and boardview files and such. the second lvds channel coming out of the ICH, they are unconnected? No traces at all? I know before someone mentioned they would try to hookup to have 2 channel LVDS and such. Just wondering.

You're right, the second LVDS channel is unconnected. Only pads on the top layer. Same as eDP.
Technically, it's possible to remove the hub, solder thin wires to LVDS pads, put the hub back on it's place and replace 28-pin LCD connector with 40-pin one for dual channel LVDS, but I doubt this approach would work because wires under the hub will emit and receive EMI, which will distort both LVDS and other nearby signals. I don't even mention that removing/installing the hub is extremely difficult procedure which many repair shops are afraid of.
Regarding the same concept with eDP - that's even more difficult, because it uses >2GHz frequencies (compare with 400MHz LVDS) and tolerances are far more strict.

nitrocaster wrote:BIOS mod is required to disable LVDS output so that it would be single display mode instead of duplication mode. I suppose the price would be around 60 bucks. Don't know shipping costs yet.

Is it possible to get that mod bios somewhere?
Did you make that yourself, or is it the same as from those modded X2x0 from China?
I still hope to get my "open air wiring" to work (Freiluftverdrahtung, without pcb, as we call it in Germany), and such a mod bios would then be great. If I can't get it to work... I'll just have to wait for your final kit

Neither my mod nor nb51' one don't use BIOS mod. I just said it's technically possible. And I'm not sure if I'll do it, because X230 requires hardware flasher to flash modified BIOS. X220 doesn't, though.

Ok. I have an X220, so having a modded bios would be great.
My backlight does work fine, too, with LVDS active, but I think my FHD panel is broken. Can't get an image...
Maybe I'll just get a 13.3 inch panel instead

nitrocaster wrote:BIOS mod is required to disable LVDS output so that it would be single display mode instead of duplication mode

BIOS mod would be ideal, but bear in mind that at least on Linux there's a small patch for the gfx driver that disables LVDS permanently (to save power) and grants backlight control to the eDP lane. http://pastebin.com/WF6wdfpb

harryK wrote:BIOS mod would be ideal, but bear in mind that at least on Linux there's a small patch for the gfx driver that disables LVDS permanently (to save power) and grants backlight control to the eDP lane. http://pastebin.com/WF6wdfpb

Sure. It's just not a universal solution.

Still waiting for your final kit . Seems great so far.

Some questions, if you have the time to answer them?

1. What's the best 1080p screen to use as an upgrade for the X220/X230?

2. Are there any disadvantages, aside from cost, of swapping out keyboard + screen in X230 versus just swapping out the screen in X220 (in both cases using your final product)?

Currently I have two screens: LG LP125WF2-SPB3 and AUO B125HAN02.0. They have some differences:
1] Physical dimensions: LG is easier to fit in the lid
2] Brightness: 400nit (LG) vs 300nit (AUO)
3] Response time: 25ms (AUO) vs 35ms (LG)
4] Maximum PWM frequency: 10KHz (AUO) vs 1KHz (LG)
The price is about the same. Both panels are 6-bit (52% NTSC, 262K colors). There are also 8-bit panels (72% NTSC, 16.7M colors), but they are much more expensive and difficult to source.

Also, it seems that X230 is still affected by low color depth issue which is presumably caused by the bug in the display driver for Windows. Chinese blogger says that X220 is exempted:

I was encountered with this trouble as many other people who holds the x230 laptop. However, x220 series will not be affected if it uses a modified driver provided by the inventor of the adapter. This bug will cause a 16-bit-like color output on the screen panel, such that the gradual change of one color will not be so smooth as it was. If anyone remember the 16-bit color depth on the earlier LCD panels, that’s the feel. The root of this bug lies in the display driver, but no solutions has been ever given till now.

I haven't yet tried to find this driver, but can confirm that this issue is present on X220. That's the case when Linux users are really happy

Regarding the keyboard swap: you are going to swap the keyboard bezel as well for the perfect fit. I don't see any disadvantages.

Would it be possible to go all the way and install a 3840×2160 screen such as http://www.panelook.com/NV125QUM-N81_BO ... 26731.html ?

Not with the current kit. Maybe it would be possible with the next versions. HD3000/HD4000 doesn't support QHD either.

Work in progress.

Nice and clean.

Looks great! I must get one or two of those boards from you next time I visit Moscow...

Finally flashed and installed the adapter on X230 board. Going to make final adjustments in the firmware and we'll be all set.



The only problem now is eDP cables: they're quite difficult to source and I got only 4 pcs. Will keep you guys updated.