Jump to content

Lenovo ThinkPad T420 with UEFI Only


Go to solution Solved by tluck,
5,249 posts in this topic

Recommended Posts

Hi Tluck,

Bios is 1.46, I will try today a CMOS reset. Good idea.

 

Video glitches: it happens about every 2 minutes, a short blackout of the external screen, linked via DP to the T420, like a short interruption in the signal.

Never had the problem before. Internal screen has no problems.

Hardware seems ok.

With the last Chameleon 3994 I've got sometimes the error:

Bad CMOS Checksum, at boot

 

 

I started occasionally getting that after flashing to modded 1.46, but it went away after tweaking some BIOS options. After flashing the BIOS my external USB keyboard and mouse stopped working in BIOS and Clover menu though.

 

Has anyone gotten wake from USB keyboard/mouse with this T420 setup working by the way? I've tried tweaking the USB options in config.plist (as per googling the issue) but no dice so far. Only wakes up from Fn-key on the laptops own keyboard.

@gpspl -

ok . will look into this older method when i have time. i take it, this is working for you better?

 

what is patch "13" exactly ... is this it: graphics_PNLF_ivy_sandy.txt ?

 

if so, thats good as this patch for PNLF was the DSDT back in the Yosemite (and before) days. but when ACPI broke, rehabMan developed the IntelBackLight approach. and that worked for 2 years now. 

@jiivee82 Have the same issues with USB KJeyboard and Mouse in BIOS and Clover boot menu,

actually the USB Keyboard never worked. Somebody experiencing the same?

Is there a 1.46 BIOS version around without this issues?

 

EDIT: Do you remember the tweaks on the BIOS to overcome the bad checksum?

@jiivee82 Have the same issues with USB KJeyboard and Mouse in BIOS and Clover boot menu,

actually the USB Keyboard never worked. Somebody experiencing the same?

Is there a 1.46 BIOS version around without this issues?

 

EDIT: Do you remember the tweaks on the BIOS to overcome the bad checksum?

 

Don't remember what exactly, but I was trying to fix the keyboard/mouse-issue, so something USB/power-related probably.

well good news. there seems to be a brightness fix for 10.12.4 ...

 

Turns out to be simple matter of each person creating the Injector to match your Panel to get full range. The brightness change is not as smooth on the transitions as with IntelBacklight.kext but there is a full brightness range. and no DSDT edits needed for me.

 

i'll post a new zip with the script to create the injector later today.

Edited by tluck
  • Like 4

In prep for 10.12.4 with brightness  changes, I updated the zip and added RehabMan's AppleBackLight Injector method. There is an Injector in the kext/Other folder which matches my LCD model 02e2 - which is an LG (or as it shows in the EDID 30e4e202)

 

- I modified the script and Panel template to match the max of the SandyBridge framebuffer  and scales brightness in 17 steps from 0 to 4882 (0x1312).

- This method (and kext) will replace the IntelBacklight.kext. Note: the real nice and smooth transitions are gone but we get a nice full range again. No additional DSDT patching was needed. 

 

Please let me know if 1.49 modded bios is working. i don't really need it but it would be good to know that it is not risky.

  • Like 1

Decided to do a fresh install on my T520 using a 10.12.3 image. Cannot get to the installer. Screen shot below when running in verbose boot mode. The T520 has modded bios 1.45 (latest I could find with a whitelist). The progress bar on the apple boot screen makes it to the end and the activity light still flickers but will not launch into setup. Any suggestions?

 

 

post-562264-0-05136300-1488046087_thumb.jpg

Any way to turn down the trackpoint sensitivity? Mine still flies across the screen with even the lightest touch. Also, if I sleep and wake up the laptop, sometimes the trackpoint and trackpoint buttons stop working all together.

I wasn't able to find a way to search for text "trackpoint" within just this specific topic (most forum software has a within-topic search), only the whole forums, so sorry if I am asking something that has already been resolved.

no idea. the screen shot doesn't provide any help. does the installer have the same Clover ESP as from the HD?

No, I took the one from the latest .zip file and copied that to the USB installer. I'm installing this as a fresh install to a new mSATA drive. Has anyone used the 10.12.3 build with the T420 folder to do a new install?

 

Edit: I ended needing to replace the DSDT files in the EFI folder with ones from a T520. That was only way I could get the USB to boot to the install screen

@149113

- well sure the DSDT in the zip is just for T420. 

 

@TheChuckster 

-what is your system? are you using the DSDT from the Zip that provides an identifier for T420?

The VoodooPS2 kexts  will then match to this model identifier and  will use a modified set of parameters to fix TrackPoint/TrackPad speeds etc.

No, I took the one from the latest .zip file and copied that to the USB installer. I'm installing this as a fresh install to a new mSATA drive. Has anyone used the 10.12.3 build with the T420 folder to do a new install?

 

Edit: I ended needing to replace the DSDT files in the EFI folder with ones from a T520. That was only way I could get the USB to boot to the install screen

 

I was able to get a working 10.11.6 T520 with these files including DSDT. I just rename matched resolution config.plist to install it.

 

Have you tried to install to a standard SATA drive? Can you upload that DSDT to try it?

I was able to get a working 10.11.6 T520 with these files including DSDT. I just rename matched resolution config.plist to install it.

 

Have you tried to install to a standard SATA drive? Can you upload that DSDT to try it?

 

Here's the one that I created for my T520. It was the only thing I changed to get it to boot. Everything is up and running now with no issues.

 

I don't remember changing that for El Capitan but that was a long time ago.

DSDT.rar

Here's the one that I created for my T520. It was the only thing I changed to get it to boot. Everything is up and running now with no issues.

 

I don't remember changing that for El Capitan but that was a long time ago.

 

Thank you. I'll try it with sierra.

 

tluck, Thank you so much for this guide! It was super easy to make dualboot Mac/Win on my t420. 

 

I ordered compatible MacOS wi-fi module on ebay, but found a cheap solution for now: I use USB wi-fi dongle D-link DWA-131, just for 5 $.

 

Works flawlessly! Thank you once again!

 

 

 

×
×
  • Create New...