NP900X4C - Black screen

[Rakurai]

I feel silly posting this, because there are so many others who have a similar problem, but I am having no luck using solutions in other threads.

 

After installing ML, I was getting a black screen, so I followed other threads, including trying the 4 patched DSDT files in this thread:

https://osxlatitude.com/index.php?/topic/2525-samsung-np900x4c-black-screen-problem/

None of them got the laptop's display working, but #2 got the HDMI working, so I used that and did the full EDT patching for this model.

 

Afterward, it got weird.  The screen worked, but HDMI didn't: I discovered that it had replaced the DSDT that I had installed.  OK, so just to test, I changed org.chameleon.Boot.plist to use the modified DSDT2.aml, and rebooted.  The HDMI output started working again, but the laptop screen stopped, even without HDMI plugged in.  I rebooted without HDMI plugged in to test, sure enough, the laptop screen goes black right when it should bring up the login screen.

 

So, I changed the org.chameleon.Boot.plist back to normal, and it still doesn't work.  I can't get it to use the laptop display anymore.  The configuration is back to the way it was after I used EDT, so I really don't know where to go from here.

 

EDIT: DSDT=0 and GraphicsEnabler=No gets the laptop display working, but its hardly ideal, plus then HDMI doesn't work.  I also edited my EDT-provided DSDT to get HDMI by changing one of the octets in the ig-platform field, and sound is working by installing VoodooHDA 3.

 

EDIT: see below for DSDT edit that got my display working

 

Any suggestions?  I have a feeling that there is some dumbly simple thing that is preventing the laptop display from working, especially since it was working before.  I can post whatever config/files.  Thanks in advance.

[Rakurai]

I got the internal display to work by modifying my DSDT.  Using this guide http://blog.stuffedcow.net/2012/07/intel-hd4000-qeci-acceleration/ and diffing a DSDT that made it work, I found that my machine must be allocating 64mb of RAM for video, so adjusting the fields in this section made some differences:

 

Method (_DSM, 4, NotSerialized)
{
    Store (Package (0x08)
    {
        "AAPL00,DualLink", 
        Buffer (0x04)
        {
            0x01, 0x00, 0x00, 0x00
        }, 
        "AAPL,ig-platform-id", 
        Buffer (0x04)
        {
            0x02, 0x00, 0x66, 0x01
        }, 
        "hda-gfx", 
        Buffer (0x0A)
        {
            "onboard-1"
        }, 
        "model", 
        Buffer (0x17)
        {
            "Intel HD Graphics 4000"
        }
    }, Local0)
    DTGP (Arg0, Arg1, Arg2, Arg3, RefOf (Local0))
    Return (Local0)
}

Changing the values of the Package (as shown by a different DSDT that got the internal display working) and the first octet of the platform ID got some things working, according to this table:

Package    PlatformID#1   Internal   HDMI
0x08       0x02           No         No
0x08       0x03           No         YES
0x08       0x08           No         Garbled
0x08       0x09           No         Garbled
0x0C       0x02           Yes        No
0x0C       0x03           Yes        No
0x0C       0x08           Yes        No
0x0C       0x09           Yes        No

I'm new to DSDTs, so I didn't realize that the hex number after Package is the number of key-value pairs that will follow, x2.  So, 8 should be correct in this case; that must mean that overrunning the number of fields actually specified (by using 0x0C) must be mangling something farther down, which I guess is disabling the external display and letting the internal work.  I'm going to assume that in my particular case, a ig-platform-id of 01660003 (but in little-endian) is correct.

 

So, at this point, I can use two different copies of an otherwise identical DSDT, one for internal and one for external graphics.  The holy grail, of course, is to use BOTH displays, but I would settle for one or the other without a reboot.  Any ideas on where to go from here?

Edited June 16, 2013 by Rakurai

[szuja]

Hi Rakurai

What exactly model of laptop do you have. I've got the same problems with black screen. I've gave up after week of trying:(

[Rakurai]

Hi Rakurai

What exactly model of laptop do you have. I've got the same problems with black screen. I've gave up after week of trying:(

I have the NP900X4C-A01US.  How far have you gotten with the install?  On mine I had to fix the DSDT on the USB key to get it into the installer with the trackpad working.  Do you have an external monitor and mini-HDMI dongle?

[szuja]

Ive got A02PL. I can install OSX 18.3 with DSDT=0 flag but it dosnt work well. When i tried modified DSDT by Emlydinesh on this forum it sometimes work sometimes not. I was random. At first i thought it was power suply problem. It dosn't work without power suply. But after install on connected power OSX boot in black screen. I dont have trackpad problem. I've got external monitor and it works in installation in mirror mode. But as i say after restart both monitors die:( 

[Guest]

first off, are you using the osxlatitude method? also, tell me if you have intel graphics card or nvidia. Nvidia shouldn't have an issue running mountain lion, but intel graphics needs more work and ask the admins for more help. On EDP, you could choose another laptop model with similar hardware

[Rakurai]

Yes, for me this was straight OSXLatitude, 10.8.3 with the recommended bootpack.  The graphics are Intel 4000.

 

@szuja: Can you get a DSDT editor and take a look at the graphics section of the DSDT that works sometimes for you?  Search the text for "ig-platform-id" and you should find it.  Or, if you post it here I can take a look.

[Guest]

Try another boot pack but one with similar hardware specs. An easier option: get ur hands on a copy of lion- there is more compatibility there.

[crimsonredmk]

Sorry for bringing back a dead thread but did you ever get QE/CI working Rakurai? I have the internal screen working using 0C/02 on my X4C but no QE...

[Rakurai]

Sorry for bringing back a dead thread but did you ever get QE/CI working Rakurai? I have the internal screen working using 0C/02 on my X4C but no QE...

Mine turned out to be unfixable due to a strange EDID of the Samsung panel, so I can't make a useful recommendation. If you have the internal display working at all, getting a custom DSDT made might work for you.