Discussion in 'Hardware Components and Aftermarket Upgrades' started by Casowen, Jan 17, 2019.
How would you connect the panel to the computer then if the cable connector has different pitch
Can you illustrate with some picture links what your referring too? All 30pin edp interface links are the same, and I am not aware of any "pitch" standard, and of all 3 panels i have used, none of them seem to have the issue your talking about.
i think the right comparison would be this: http://www.panelook.com/modelcompare.php?ids=37089,23899
about the pitch, i really dont know about that, but the original screen on dell 7530 uses a edp1.3, the "new" screen uses edp1.4, so, this could be a incompatibility.
but, back to boe nv156fhm-n4b, i notice some atualization on panelook, now list suport to gsync, a don't remember to read that before. I was ready to buy for my acer helios (g3-572), because a lot of people had sucess with a acer nitro 5 (an515), but one review on aliexpres worried me.
anyone tryed this screen on acer helios, had some problem? A custom resolution utility could solve this?
Just installed this panel into my Dell Precision 7530 (upgrade over the 45% gamut screen) and its definitely a huge upgrade - much richer colours, nice contrast, everything is a lot smoother. Downside wise this screen definitely uses PWM for any brightness setting bellow 100%, so will need to use it for a few days / week before I see how it affects me. Has anyone managed to find any calibrated profiles for this panel?
I couldnt find any, that said those are usually done per panel with an easily obtainable calibrator, usually from a local computer shop. An easy way to over come PWM is just to lower brightness and contrast in the nvidia control panel, though I rarely do that, and the PWM for me isnt noticeable. I personally doubt that it even needs to be calibrated, and in all likelyhood that was done at factory.
NV156FHM-N4B coming in the mail soon. It's going into a low end HP 15-bs234wm with Pentium N5000, but the platform supports eDP 1.4 and the connector has the same pin pitch as my original screen. I'll update soon.
Edit: I just installed the NV156FHM-N4B. And. It. Is. ****ING AMAZING BOYS. HOLY ****. It looks so good and I can't believe it worked right out of the box. Such contrast and color depth, much refresh rate! Brightness control works. And yes this is in my HP with the N5000 processor. Yes it's real ****ing life.
One issue that I had predicted may happen with my particular laptop, power issues. At max brightness at 144Hz I quickly get black screen with flickering, and at max brightness 60Hz the screen cycles between on and dark every half-second or so. So I'm pretty sure it's a power issue. I think I can get away with 144Hz at lowest brightness and I actually only use laptops below half brightness anyway, usually at lowest. But I could live with 60Hz to be safe, especially when I wasn't even trying to find a 144Hz screen when looking into panelook models. The stock screen takes 1-2w less power and my laptop is naturally a very low-power model, but it could be that or a timing issue, probably power though. I speculate that if it's power, it might be related to there only being two dedicated wires for LED backlight in my stock eDP cable even though there can potentially be up to four. The two LED backlight power wires come from the board and then are soldered to two pins each at the display side connector, 26+27 and 28+29. It does have both data lanes though, otherwise none of this would be possible at 1080p. I also think it could be minor differences in voltages between the original and the N4B but they surprisingly match very well in the datasheets.
My previous stock screen was supposedly marked for 8ms response time, and the N4B 16ms. I honestly don't notice a difference. It's feels great, and it's also the first 120Hz+ screen I've ever owned. And I've only actually used a high refresh monitor once in my entire life, at a Frys a few years ago.
I will be working on color profiles to see if I even need to get it towards a certain look. I'm so used to the higher gamma levels on my last monitor (necessary for that case) that gamma does look a tad low, but again I'll mess with it more. From what I can tell though, it looks very good and neutral right out of the box.
Incredible 1 week with this laptop. I got the RAM upgrade, the backlit keyboard, and now a beautiful display all in just a few short days. So ****ing hyped.
Well you might try running a custom refresh rate of say 120hz to see if that lowers energy enough. Maybe putting system performance on maximum? Have you tried using throttle stop? If those things dont work, mess around with refresh rate till your at a stable frequency or brightness level, and you can always artificially make it all brighter via raising the gamma. How bright are you able to get it, and at what frequency? I can technically run full brightmess for instance, but usually dont go past 85 percent during the day.
Mine didnt like getting set at 60hz a few times, but its okay with say 96hz or 75hz for whatever reason. Maybe it is a timing issue as you said, so maybe mess with screen timings? I am not sure.
As for the cable, I dont know if that will be it, but you should at least have a return policy just in case its not.
Intel command center doesn't let me use any non 60Hz/144Hz custom res, including ones like 75Hz. It says mode not supported. And I can't add 1080p 60Hz modes with different timings because it just says cannot add mode that already exists. I'm perfectly fine running 60Hz though and don't really appreciate the benefit of 144Hz as much as many others do. My original panel was 768p @60Hz btw.
But even then, things are still a bit buggy at 60Hz. There's this video I'm watching on Philipdefranco's channel, that if I run in full screen at a very specific point in the video it starts flickering the screen on and off for a few seconds. It's consistent every time at that exact spot. But it doesn't happen at all if not in fullscreen, and every other youtube video I've watched doesn't do this. And it does also happen at 144Hz, but not at all at any resolution below 1600x900. That then it makes me wonder if it's just the data lane output or firmware maybe not playing quite well with higher resolutions. So even though 1080p @60Hz is seemingly stable there are very rare bugs here and there and I doubt I can do anything about it. I'm honestly willing to live with an occasional bug. The passmark monitor test tool does report full 1080p, 8-bit color and the correct model number so I'm getting the performance I want out of the screen it's just not matching quite right with the motherboard and/or cable.
I just looked at the video again and found something interesting. If I'm moving the mouse while the video is playing, no black screen bug. If I move the mouse just before the problem area happens so that the seek bar is visible, bug doesn't happen. And when the bug does happen, the screen stays black during the entire 10 second section of the video with a specific background unless I move the mouse. Video must be fullscreen for bug to happen. The part of the video doesn't seem special so I don't know what is triggering the bug (video, bug happens at 3:45). I feel like maybe the screen is being told to turn off because it thinks there isn't enough going on or something but then why doesn't it happen at lower resolutions? It's like the screen just doesn't like the specific combination of color data it gets at that section but then is perfectly fine if the seek bar is showing.
If I could get a display engineer to talk to me that would be cool. I'll probably go back to the datasheets but to my memory while the main voltages (3/3.3/3.6, 5/12/21) all matched, the two sub-voltages that are 2.0v on the stock screen are 2.2v on the N4B, and max total power usage is 1 or 2w higher. It's also possible the cable passed validation for lower resolution but didn't for higher res though I highly doubt that.
Timings are very confusing to look at but I did notice a lot of the values weren't the same. Not sure what the unit was but I assumed it was in ms, and a made up example would be, stock screen 100, N4B 200 for the line 32 vsync. That is from the timing table, while the pinout tables match very well except the N4B additionally has the H-sync out at pin 24 while the stock screen has it not connected. I've seen datasheets for other G-sync monitors where it says pin 24 H-Sync is optional so I assume this probably doesn't have much to do with the problem as I'm not using G-Sync.
Edit: Now I'm having more issues. Something happened not sure what but now I black screen if I'm viewing my desktop without any windows open. If I change my background the desktop is fine. Moving files or icons doesn't help much when the stock background is in place. But if I change display scaling to 150% no more flickering. The desktop wasn't doing this before so I'm not sure what I changed. I'm just going to use the old original Win10 background for now, found it in 4K online.
I ran through the passmark monitor test, and I get black screen on all of the solid color slides. So I believe what could be a problem is when the colors on the screen aren't diverse enough, not sure why that would happen though.
In this color test video I can watch it fine regular screen but in fullscreen, I can't see anything when the frame is on red or blue. Green is fine though. So something is wrong with color data coming into the screen. It can show these colors but not when...there is too much of one shade on the display? Doesn't make sense to me. I can even have it in regular screen mode and as I zoom out to make the video player larger, once I hit 33% then I get a black screen. So it's not necessarily fullscreen but a certain upper limit ratio of a specific shade of red or blue being too much and then black screen. Seems like that percentage limit is somewhere around 2/3 of the screen.
Update April 2020: I no longer use the ICC profile with reduced color range as I really want to use this display to the best it can be. For a while now, whenever there is a problematic website I use my adblocker to block the problem element (usually a banner or notice), or I just downsize my browser when I use that website. Videos are 99.99% fine, with only very rare videos having a few problem frames. I was using stock gamma for a while but eventually had enough...the contrast ratio is too good for standard gamma to be optimal for me, so I now use an ICC profile to bump gamma slightly. The display has been good to me for the past few months considering it was a totally unsupported mod.
The problem is likely due to the eDP cable power wiring not being complete. Could be fixed with a mod to the wiring in the cable by adding wires so power pins aren't sharing wires.
This is going to sound really, really strange, but I think I solved the black screen issue for the NV156FHM-N4B in my HP 15-bs234wm by using the color management calibration tool.
Currently I use the monitor without the ICC profile because it does slightly reduce luminance range, but if you need 100% stability this will work. Without the ICC profile I run into the black screen issue so rarely that I can go an entire session without it happening, and even then if it does happen it only happens for a few frames in a rare YouTube video.
At first I was researching and trying what made "sense" but eventually got desperate and started trying every random thing I could. So I decided to see if lowering red and blue levels would allow me to watch the red and blue frames of the pixel test video in full screen without black screening. And it worked. So I lowered all R/G/B equally by about 6 notches to preserve color balance and now I believe the black screen issue is solved. This is in tandem with lowest brightness, so to go brighter I'd need to lower the colors even more in the calibrator. For middle brightness I need to lower by 8 notches. To pass the RGB switching section of the video in full screen I need to lower by 15 notches. Passing every Passmark monitor test including the r/g/b gamma pages requires doing down by about 24 or 25. And yes, it works at 144Hz too. And from what I can tell, the picture quality isn't affected as long as the values are lowered equally. It just means you will need to raise brightness by a notch to match what you had by default.
I still don't understand what is going on and have lots of questions. If it's power related, is it just a power issue with the red and blue subpixels? Did lowering the color levels in the calibrator tool squish down the effective color depth that Windows outputs? Is the data output on my motherboard not prepared to send 8-bit? Maybe a different than expected ratio of sub-pixel voltage to LED voltage since my original screen had a lower minimum LED brightness? Very strange situation.
It may be possible that you have a defective screen as well. I recommend either taking it back and just trying another IPS panel that is 60hz. To be honest I am also not certain.
Separate names with a comma.