eDP screens on Clevo's

Apparantly the eDP screens on CLEVO's can be switched between models.

i.e you could have an older model, maybe a haswell machine, with say 1080p screen, if the motherboard has the eDP port and cabling you could change the screens to the 3K or 4K ones from newer models, like the ones that have the 6700K Skylakes that come with 4K screens.

Anyone else tried this yet ?

Parts are available, easily, but maybe some of you have successive models.

 

Yes, see here. Running 4k depends on whether it featured a 4-lane connector, rather than the 2-lane minimum required for 1080p. That means it either had 4k or 3D 1080p panels as an optional upgrade. Especially the 3D (+eDP) is interesting, as that was available at least as early as the 2012 P370EM, unlike the 4k panels. Actually ... even the 2011 P170HM will do.

Thing is that it needs sufficient bandwidth to run (at 60 Hz) and the eDP 1.2 common with these older Clevos can do ~4.3 Gbit per channel (20% overhead) and since the 3D stereo vision models had 4 lanes (some erroneously labelled) that equates to roughly 17 Gb and an 8-bit 3840×2160 @ 60 Hz requires around 12.5 Gb. It's not much leeway, so overclocking to 80 Hz is pretty much the theoretical max. (provided the screen itself is capable), but it's enough to run the AUO B173ZAN01.0 at its native 16.7M colours.

There's no plug-and-play cable though, afaik. The new Skylakes and the ZM desktop cpu models use a 1x40 (1 row, 40 pins) push down connector, whereas the older eDP models use the 2x15 'block' type. Even if you already had the 3D cable then the lcd end is incompatible; 50-pin vs. 40-pin. So what you need is a full-fledged cable for the motherboard end (the fhd versions lack necessary pins) plus one more for the 40-pin lcd side and splice the appropriate wires back together. The lcd-end cable is easy enough to find; many displays use the same connector and pin-out, regardless brand of laptop or even lcd manufacturer. The motherboard cable may be tricky as 3D models weren't that common. A good alternative is using the W230Sx QHD cable (6-43-W23S1-010-K), since this has all 30 pins connected, thereby making it compatible with all 2x15-pin eDP Clevo models.

There's also the 5V -> 3.3V to deal with, due to the eDP 3D panels requiring non-standard 5V lcd voltage, rather than the standard 3.3V. A resistor or power-switching mosfet will do, but for the 30+40 pin models it should also be possible to trick PLVDD to output 3.3V, just like it does when an LVDS panel is connected. From the looks of the schematics it may be as simple as powering the VGA_ENAVDD pin.

Anyway, a cursory glance suggests that at least all P37**M, P6**S*, the P170HM and P570WM should be compatible with 4k. There may be a few more and with some models it depends on the motherboard revision; did it have an eDP or LVDS panel to start with? A lot of them have the 30-pin eDP + 40-pin LVDS layout, so these can run both.

 

In some cases the boards had two connectors, one for eDP and one a standard LVDS, the eDP one might not be soldered on the board in some cases.

 

Yes, it's working perfectly. I took time to understand flickering wasnt due of voltage or amper, but mostly because display is very 'sensitive' to ground. I had to protect all frame to avoid any contact between display and any metal body or wifi antenna. From that, all is perfect didnt notice any issues for months.
I will connect back the lvds for power and edp to drive it. Like that no need external driver.

 

The LED driver could pick up noise in the panel yes, usually the area is shielded.

 

I just had a look at the specs of the W230Sx eDP schematic, am I correct in my interpretation that due to completely different eDP port wiring this cable is NOT plug and play into the P370EM, and needs re-wiring in any circumstance?

 

Yes, that is correct.

The W230SS or SD QHD cable is physically pnp for the motherboard-end, but its pin-out is not, so this needs re-wiring. And for the lcd-end you still might want another 4-lane 40-pin cable. Even though both are 4-lane and pin-compatible the cable from the 13.3" model can't physically reach the lcd connector of the 17.3" systems. You could, of course, cut the SS/SD cable in half, splice-in extender wires, swap them accordingly and resolder. That does leave two potential failure points rather than a single one, but it shouldn't be a problem if you make nice, long solder joints and keep both locations somewhere stable, meaning anywhere except close or through the flexing hinges.

Main thing is to remember that the 3D-generation systems are outputting 5V logic voltage on the eDP port since that was what their 3D panels required. The modern 3k/4k panels are using the standard 3.3V, so make sure to check the P375SM-A upgrade thread for various methods to work around that. Just to be sure; 5V on a 3.3V panel will either kill it outright or, if you're lucky, trigger a fuse on the panel's pcb.