[SUCCESS] P377SM-A 4K Display Upgrade

from which schematic you definite Pin25 ? i would like to know so i can disconnect it to stay at 3.3v without converter

 

What process you would like to have in video?
-i have in my playlist how to switch display in this laptop. then you will just need to mod the cable and a bit the barbone of lcd to be able to fix lcd.
-Modding the cable is easy, if you buy the right edp w230ss wqhd cable, then you will just have to unpin and plug them like in my 4k schema. Then from aarpcard removing the pin25 to be good.
-Modding the lcd barbone is about removing a metalic frame, isolating metal contact with display and antenna, creating and fixing display support in top of metalic frame to fix display, and some little dremel play.

 

Pin 25 on the motherboard connector.

If you look at the below schematic Pin 25 on the motherboard is the PLVDD_Sel signal. Highlighted in green, is where I connected it to 5V, which is enough to trigger it. (Of course you will have to leave that pin floating, not grounded in the actual cable.)

 

Thanks. will try it as soon

 

Let me know if it works. I only did the mod and measured it with a multimeter to confirm 3.3v - didn't work with my screen, but I'm assuming it was due to the other issues with my cable.

@clevo-extreme Thanks so much! I just ordered a QHD w230ss epd cable from Clevo Extreme.

 

not working. i remove pin 25 and let it disconnected from anything. screen stayed black but it was powering 3.26v

 

is there a plvdd in lvds connector where to connect this pin 25? didnt find it..

 

I connected pin 25 on the edp connector to the 5VS rail, by way of pins 1, 2, or 3, on Q6.

 

So i have to connect from this q6 to edp connector right. Will take a try like on your picture

Edit: not working, screen stay black.
I think the easiest way is to connect power and ground from lvds. but last time when i try it, idk why even lvds output 5v with a mod cable. Only with my original lvds i could output from lvds 3.3v. I dont have it anymore, i used some pin from it. if you still have the lvds, take a try from it also.

To be sure it wasn't working, i always tried the monitor running at 5v to be sure cable wasn't wrong.

 

Hmm very interesting. I'm going to try running my screen today at 5V and see if it works. (I still suspect its some other issue with my cable.) But if it works, then that would be very interesting.

What voltage are you using to run the screen at with your variable regulator? 3.3V? Why would one source at 3.3V work and the other not work?

 

i already run for weeks ( max 2) at 5v when i didn't have driver. it was working good. I have no proof that 5v cause my screen "ghosting" but i prefer to think yes. Actually, i set it at 3.45v.
i dont remember but i think it has also working at 3.2v while i was adjusting it.

It was working at 3.3v from lvds or driver BUT with lvds i had black flashing... it was the time when i didn't put any protection against ground with display... I understood this issues later. Too bad my lvds cable was already destroyed.

 

Also, now the issue i have with lvds, if i try to respect pins ground and vcc pins for lvds connection, i got 5v output. I thought lvds only give 3.3V.... So somewhere there is a trick to make it decide 3.3v or 5v. This trick is a pin in lvds motherboard output. Wich one idk....but if you connect original lvds cable, you will have 3.3v. If you connect only vcc and ground pin in lvds, you have 5v. Hope you understood what i mean )

 

So i tried again to power from lvds:

If i connect from lvds ''plvdd" instead of "plvdd sel" from edp: cable burn lol....
If i connect as ground Pins: 21 27 31 and pins 22 28 34. As power VCC only 12 16. ==> From lvds. I got 3.1V BUT screen works. After a game, its weird.... this can be due of bad quality connection cable, or i guess more because its only 1A. All data info from schematic.
If we can find a way to ouput close to 3.3V and at least 2A, we will be good i think

 

The 4k panels do eat a fair amount of extra juice, the 4k stock models had to take this into account with their cable.

 

So I got my cable in the mail yesterday. I repinned the motherboard connector and tried it out. By pulling pin 25 high, with the cable disconnected from the screen, the output at PLVDD was 3.125V. With the screen plugged in, this dropped to 1.998V. The screen did not turn on. Next I tried pulling pin 25 to ground. This resulted in the output at PLVDD being 5.165V. With the screen attached, the output at PLVDD stayed at 5.165V. The screen turned on, but stayed black and was not recognized by windows.

I triple checked my pinout for the connector and am 99.9% sure it is correct. I'll take a look at it again today with fresh eyes. I'm also going to use a buck converter to set the voltage to 3.3V, as I suspect PLVDD being too high at 5.165V being the issue. If the power rail is too high, the differential pairs might not have enough difference between them in comparison to power and ground to register correct data.

I don't know why PLVDD drops to 1.998V when pin 25 is pulled high. Looking at the schematic, I can't explain this other than that perhaps the screen is pulling too much current. However, if this was the case, I would also expect PLVDD at 5.165V to drop at least a little bit too.

So my issue is either PLVDD being too high which I'll try to fix tonight, a bad screen, or a messed up cable. I doubt it's a bad screen, as they seem pretty robust, but it could be the case. When I was unwrapping the cable to repin it, I accidentally severed the complimentary wire of the lane 3 differential pair. I repaired it by soldering the two ends back together, while trying to ensure the length of wire was preserved.

I don't have much experience with differential pairs. How critical is it that the lengths of wire be identical and tightly twisted? Would one wire being a couple of mm shorter than the other result in data corruption? I tend to think not, but I don't know for sure. Maybe someone can chime in on this.

EDIT

@DARCODER

Did your w230ss cable have the high speed ground wires for the 5 differential pairs? Mine did not. I'm assuming they weren't needed since the cable in that configuration works fine with the QHD screens in the w230ss. In theory, they are used to shield the signals on the differential pairs from crosstalk, so not having them could result in data corruption, but I feel if they were necessary for this application, the engineers would have included them.

DOUBLE EDIT:

So the more and more I read about differential pairs, the more I'm convinced my repair would not have destabilized the pair. It's far more likely it's a PLVDD voltage issue. Both 5.165V and 1.998V are WAY out of spec for the panel. Crossing my fingers 3.3V will solve it.

 

That's weird even full connected for 5V you screen stay black...mine works if everything is plugged.
What i know is that if everything is connected, i dont have 5v but 4.65-4.85V to be specific.
What i also remember (hope im not wrong) is that the pin 25 is linked with all ground, i mean: if i test with multimeter an connection with any grounds pin and pin25, i got a sound meaning pin 25 is connected with ground.

Also about lenght cable, to connect my converter, i had to add lenght cable, meaning my converter is fixed in the location of Fan's gpu 2. i have more than 15cm for both grounds and vcc.
When you test/run the screen, the panel cant touch any metal frame of the barebone.

 

With everything hooked up the 5V PLVDD stayed at 5.165V. Didn't drop even-though the screen turned on and stayed black. My guess is that's too far out of spec and maybe the 4.65-4.85V you got worked because it was closer to the absolute maximum rating of 4.0V for PLVDD.

Did your cable from the w230ss have the highspeed ground connections for the twisted pairs? Specifically pins 2, 5, 8, 11, 14, and 17 on the LCD side. Mine were all no connects. Ultimately I don't think it matters, but it'd be peace of mind for me to know if your's was the same way and it works.

 

i dont know, i didnt open the cable, i just unpin from motherboard side and rearrange all of them. What i know is that Ground pins and highspeed grounds are all connected in a same pin at the end. Because they all both ( vcc and ground) go to converter then to the screen.

You can see on my schematic in post 1 they all are with 'G' letter means i plug them as ground
http://forum.notebookreview.com/attachments/plan-schema-2-jpg.131865/

 

So the screen turned on at 3.3V, but still stayed black. Not sure what's going on here. Cable is definitely pinned out correctly. My suspicion is the screen might be bad. Either DOA or I killed it by trying to run it at 5.165V. Shame I don't have any way to test it. Screen prices have come down a lot so I bought another screen to try. Worst case scenario is they're both good and I'll sell one when I figure this whole thing out.

 

i allready tried my screen at 5.15V and it was working. i hardly believe 5v kill the screen. i still dont think with death screen , something is not well plugged i guess more. Did all ground are all connected together? did you split vcc in 3pins( 1alone,1alone,2together) Then you need to check if you didnt inverse motherboard pin connections, i allready did that mistake, i notice it with ground connections, where ground pins between 15 and 33 (from my schematic numbers) where in the other side....

 

Which panel are you using?

 

I'm using the B173ZAN01.0 panel. Specifically the one below. I'll have another look at the cable, but I've gone over it like 20 times and am really certain the wiring is right.

http://www.ebay.com/itm/17-3-Panaso...378404?hash=item3aa0c52764:g:f2oAAOSwYmZXM~KE

My cable only had two wires for PLVDD, not four. Shouldn't really matter for short term testing though.

I'm certain the twisted pairs are in the right orientation. When I reverse a pair, the screen doesn't even turn on. I'll check the other wires later tonight.

Maybe one of the wires is broken or something, I'll check continuity too. I can't help wondering though if I somehow damaged the panel by using the frankenstien LVDS cable I made.

 

That looks like a compatible ones. The original one is made by AUO. You sure that wont be an issue? Sometimes the specs are slightly off for different manufacturers.

 

i also have only 2 vcc from cable, but i split them i dont know how since vcc from mb in edp request 3 pins.

 

Is your panel from AUO or a different one?

 

So I checked continuity on the cable. Everything is fine. I also double checked the wiring again and now I'm 100% certain it's not the cable. I'm getting more and more convinced the screen might be dead.

When checking for continuity, I made an interesting discovery. All of the ground pins (2,5,8,11,14,17,23,24,25,26,28,29,30, and 31) on the LCD side connector are all connected together eventhough there are no wires physically running to them.

Additionally, Pins 36,37,38,39 are all tied together and pins 18,19,20,21 are all tied together eventhough there are only 2 physical wires per set running to those pins.

I haven't tested the LVDS connector, but I suspect it is the same story, just with a different pin-out. This means eventhough I wired the LVDS connector correctly, I might have shorted some pins on the LCD to pwr or gnd that shouldn't have been and fried the screen. I'm almost certain that's the issue I'm having.

I'm just hoping nothing got fried on the motherboard side. I'm gonna probe each pin on the mb with a multimeter and oscilloscope to try and make sure everything is OK there.

 

So the motherboard was definitely fried. With my old LVDS 1080p screen connected, it exhibited the same issues as the 4k screen. Screen turns on, goes black, and stays black, but gets recognized in window's device manager.

Unfortunately, after pinning out some components, it did not exactly match the schematics, so it was hard to troubleshoot. I ended up purchasing a new motherboard. The new motherboard fixed the issue with the LVDS 1080p screen, however the 4k screen still exhibited the same problems.

So now we're kind of back to square 1. It's either something wrong with the cable or the screen. I can't afford to throw much more money at this issue so I'm probably going to buy a new cable and repin it again as a last resort. It's possible that the spliced differential pair is the source of the issue. If that doesn't fix it, I'm unfortunately going to give up on this.

 

It's such a fine pitch, messing around with the cable when I did cost me a motherboard :/

 

the easier method working is external driver. i place it between fan2 and cpu fan.
Now im waiting to buy my secong gpu and I also mod the fixation of the screen in a better way: i fix the frame of my lvds screen and instal inside the 4k screen.

 

This really sounds amazing and I really want to try this on my p377sm-a however the news that the 1080m's probably won't work in the p377sm-a is a bit disappointing and basically limits the advantage adding a 4k screen to the laptop could bring.

 

Agreed. Earlier cards just won't push good framerates in 4K so it's not worth it.

 

Hey guys,

Final update for me probably. I GOT IT WORKING!!!!

Turns out the issue was totally with the differential pair that I cut by accident. I shortened the longer wire by 5mm so the two wires in the pair were as close to the same length as I could manage, and it fixed the issue! I also have it running off of 3.3v using a buck converter that I installed in the mSata slot in the base.

Some pics:




I haven't done any gaming yet, but I've watched some native 4k videos through VLC and on youtube and everything seems to be working perfectly. So far I don't have any of the issues DARCODER reported, but it might be too early to tell for me. I'll keep you guys updated.

@DARCODER I'm having some trouble fixing the brightness adjustment issue. I followed your instructions and searched for NVIDIA, but there are tons of results. Where exactly do I create that key?

 

Nice Job
can you show me wich convertor you are using? i want liitle one because mine now is between gpu2 fan and cpu fan...i think it will burn one day

So this are all my trouble:
-ghost if you keep a bright color background for more than 3min, if 5min deeper and so on.
-some time screen turn black: i notice its because my driver touch ground.
-some time i got in blue color invisible flicker but not really flicker...i cannot explain what is it... but resolve while i move the driver.
So my last 2 problems will be off when i will take the time to fix perfectly all cable and pins. i wait to find the most little converter 3.3v.

it should be there:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000]
BUT maybe your nvidia installation isnt in "4d36e968-e325-11ce-bfc1-08002be10318}" so when you reach class, click ctrl+f and search word: Nvidia. when it will find a result, thats the folder in a "0000" folder.
Once you or it found the result. Add key Dword(32), write: EnableBrightnessControl. then add 1 as result. Restart and your good. with control center or windows, you can change brightness.
TAKE CARE of this: They accept 0% as brightness you might be in trouble if you move the mouse/pad while beeing at 0%

 

Thanks man! That worked for the brightness adjust.

http://www.ebay.com/itm/5pcs-Re-DC-...448900?hash=item33afb8b144:g:d5YAAOSwX~dWktJo

^ That's the buck converter I'm using. About at cheap as you can get and it whines a little bit, but the current output is high enough and it's small - about 1" x 2" x 0.75". I'd honestly be surprised if it lasts a long time, but we'll see - so far it's been going for about 6-8 hours a day for 3 days now with no issues. Gets a bit warm, but well within spec.

What's almost as good as the resolution on this screen is the 8 bit color instead of the horrible 6 bit color on the 1080p screen. Also seems like the contrast ratio is much better too.

 

Nicely done!

 

Could someone please post a video or steps on how to modify the p377sm-a ? I understand its a lot of work to make a video but if you have time and are willing to do it, it would be appreciated.

 

Well i have the same as you but a red board its warm but not so much. its been 7 months of use now

 

it will be hard to post a video because it required lot of work as you know and these days, i dont have much time to do it...
it need to show how to mod the barebone screen, how to create the cable, where to place the convertor. All these steps take lot of time.
Maybe one day i will do a tutorial about the cable if i want to create a better one. Mine is oversize due of reconverting/reajusting it everytime

 

It's not for the faint of heart certainly.

 

Some update,
I stop using a driver since a month, because 1 driver start to feel "ill", not maintaining stable voltage. Then another river, this time a little one as a coin who just died in a week.
For now i m not using any driver and flickering disappear and also Ghost dead screen as well. So i am totally happy. I also connected sometimes my 120Hz 1080p screen but i cannot support this "low" resolution anymore )
So if my screen will die, i will jump to the 3k 120Hz= AUO B173QTN01.0

My Final modded P377sma:

 

By "driver" you mean no step down converter and the panel is getting 5V (ish) ?

 

for me the "driver" is a 5v converter into any value you want. Here we want to be close to 3.3v-3.45V. With still keeping 1A, the screen use between 700 and 900mA.

 

I haven't posted here in years, but seeing everyone use a buck converter to step the 5V down to 3.3V makes me cringe. The motherboard has a 3.3V vs 5V voltage select. You just have to cut the PLVDD_SEL line and you get 3.3V. This is why LVDS has 3.3V on PLVDD, as the PLVDD_SEL line is missing on LVDS, so the default 3.3V is selected. You just need to make it missing on eDP as well.

 

well, i didnt cut the connection but i remove the pin from edp port. it make the screen flickering a bit.
It"s been 2 months i am using the screen at 5v without any converter, still working good.

 

Are you saying you pulled the PLVDD_SEL pin and the voltage is still 5V?

As for the screen flickering, how well built is your cable? I had to wrap mine in aluminum foil to avoid noise from the motherboard ruining the eDP signal.

 

I couldn't test the voltage hopelessly. The screen flicker a bit (noticeable in blue background ) if the plvdd is removed.
But my cable seem good, I didn't cut it, I just unplug every pins to set them in order for edp port

 

Ah, nice work. How did you get the glue off without damaging the cable? Did just Isopropyl alcohol work?

So the flickering is worse than just normal dithering flickering though? That's odd.

 

First with a cutter, i cut (perpandicular) between each pin to create less 'glue power'. Then with a needle, from inside each space of the pin, i remove it ( it should just broke or beeing removed "as a ring with the cable" of the pin). Hope you understand my english )
If we knew what is the glue model used, we could find the dissolving liquid agent.

Well at 5v, my screen look just normal, i will say near perfect ( still have a little ghost effect but only after 10mn but disappear pretty fast and noticeable only in dark grey).
If i disconnect PLVDD-sel, the screen flicker a bit in blue and if i look deeply my background, i can notice it. I don't know why....maybe my screen is dying bcse i m using it at 5v.

 

Please verify that all functions are working too including brightness control, etc. Otherwise we may need to update BIOS/EC. Keep us posted.

 

Thanks for your answer!
Well, with converter (3.45v) or without ( 5v) in edp connector with a modded cable, display is working good, the brightness control can only be adjust in control center or with windows battery. The brightness hotkey(s) don't work, that's the only issue reported.
The hotkey FN+f2 to shutdown display is working.

By the way, the laptop is from your great company