I have the 4180CM6 variant of the T420, so it has the i5-2520, NVS4200m, and 1366x768 screen.
Only changes so far:
Additional 4G module
Seagate Barracuda* 500G
Removed the Cellular card
Removed the i5 sticker**
135W T520 Power Supply**
Kingston UV500 120G mSATA***
*Yeah, it's only 5400, original 320G died and I needed a cheap-ish replacement in a hurry
**Prep for i7 upgrade
***Not the best SSD, but port is limited to SATA II/300 anyways
NOTE: Some W10 driver packages don't properly support the T420 or aren't even available, in which case use W7 or W8 ones.
Even the W7 ones tend to be newer and/or more functional than the generic W10 ones.
The T420 won't be on the "supported systems" list, but I've installed all these and used them successfully.
DISCLAIMER: This information is posted for informational purposes only. If you manage to blow up your laptop it's not
my fault. Besides I'm completely broke, so suing me would be pointless.
OTHER LEGAL: Lenovo® and ThinkPad® are trademarks of Lenovo in the United States, and other countries.
T420 Bios 1.52
https://pcsupport.lenovo.com/us/en/products/LAPTOPS-AND-NETBOOKS/THINKPAD-T-SERIES-LAPTOPS/THINKPAD-T420/downloads/DS018784
Intel Management Engine has some security issues and is useless for home users anyways.
Don't bother installing it, and disable the following thingy in device manager or leave
it as an 'unknown device':
Ports (Com & LPT) -> Intel(R) Active Management Techology - SOL (Com5)
DVD drive DLL fix!
After installing the PM Drivers and Power Management Drivers (I wish these were named more distinctively, but Lenovo) copy PWMTR32V.dll
FROM:
C:\Windows\SysWOW64\Lenovo\PowerMgr\
TO:
C:\Windows\System32\Lenovo\PowerMgr\
Intel RST 12.9.4.1000
https://www.station-drivers.com/index.php?option=com_remository&Itemid=353&func=fileinfo&id=687&lang=en
Microsoft's AHCI drivers are buggy and can cause high CPU usage.
Note1: While "Lenovo Power Management" isn't a thing, AFAIK, the drivers are still needed for Vantage and stuff.
Note2: You need Lenovo Vantage, now several of the FN keys open parts of it.
Lenovo Vantage also lets you set the battery threshold
Enable Lenovo toolbar (has some useful bits): Windows Taskbar -> Toolbars -> Lenovo Vantage Toolbar
Note3: Both versions of the hotkey features thing have to be installed
The W10 version doesn't install all the things the T420 needs, but has the updates for W10.
Note4: Synaptics UltraNav is called by FN-F8
Note5: W10 handles biometrics, you don't want the full "Fingerprint Reader Software," just the driver.
Note5: Install these items in sort of the order shown.
ThinkPad Power Management Driver 1.67.17.28 UNINSTALL OLD 'SETTINGS DEPENDENCY'
https://support.lenovo.com/us/en/downloads/ds505267
Lenovo Power Manager 10.0.106.0
https://support.lenovo.com/us/en/downloads/ds541411
Lenovo System Interface Foundation 1.1.18.3
https://pcsupport.lenovo.com/jp/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t420/downloads/ds105970
Synaptics ThinkPad UltraNav Driver 19.0.17.141
https://support.lenovo.com/us/en/downloads/ds103454
Synaptics Fingerprint Reader (WBF)(0017) 4.5.513.0 Untested, it's not on my model
https://www.catalog.update.microsoft.com/Search.aspx?q=synaptics%20FP%20sensors%20WBF
Lenovo Vantage For setting battery threshold
https://www.microsoft.com/en-us/p/lenovo-vantage/9wzdncrfj4mv?activetab=pivot:overviewtab
Hotkey Integration Features PART 1 (W7) 8.86.25
https://support.lenovo.com/us/en/downloads/ds101334
Hotkey Integration Features PART 2 (w10) 9.0.1.3 INSTALL SECOND after W7 version above!
https://support.lenovo.com/sg/en/downloads/ds031814
Note1: It took me forever to figure out which camera driver off Lenovo's site to use, these worked for my model.
This wasn't helped by Windows wanting to keep over-writing the Drivers >_<
If your camera quits working, check the drivers to make sure they're still Realtek 10.0.17134.20047 (or newer)
If Windows installed something else entirely, like Ricoh, uninstall and "delete the driver files," then reinstall the file below
Otherwise, if all else fails, uninstall and force Windows to just use "USB Camera Device"
Note 2: if the Ricoh Card reader drives your CPU usage way up:
Disable the card reader in Device manager and get an external card reader
Ricoh never fixed this issue.
Integrated Camera Driver 10.0.18362.20112
https://support.lenovo.com/us/en/downloads/ds502998
OR Force use of Windows "USB Video Device" driver if the Lenovo driver breaks it.
Brief instructions for "Forcing" the driver:
Update Driver
Browse my computer for driver software
Let me pick from a list of available drivers
Have Disk
Copy manufacturer's files from C:\DRIVERS\CAMERA\N29CA04W (default location)
Realtek -> Integrated Camera (may have to experiment with which Realtek to pick)
Update driver warning [Yes]
Ricoh Media Card Reader Driver 2.25.18.01
https://pcsupport.lenovo.com/us/en/downloads/DS038445
Note 1: Low Volume w/ Conexant audio software :
-> Control Panel -> Smart Audio -> Click headphones -> Disable "safety"
Note 2: Google for how to install the color profile, it seriously helps
Note3: 3000HD is the graphics in the Sandy Lake (Gen 2 iX) processors
Windows 10 should already have the newest driver for the HD 3000
Lenovo Active Protection System 1.82.0.20
https://support.lenovo.com/us/en/downloads/ds014892
ThinkPad Monitor INF File 6.11.1.0 (Manual Install)
https://support.lenovo.com/ca/en/downloads/ds502266
Intel Chipset Support 10.1.1.45 See below about manually updating via Device Manager
https://support.lenovo.com/us/en/downloads/ds038348
Intel 6205 (WIFI) 19.70.0
https://www.catalog.update.microsoft.com/Search.aspx?q=6205
Intel 82579ML (Pro1000) 12.15.31.4
https://www.catalog.update.microsoft.com/Search.aspx?q=82579LM
Intel 3000HD Graphics 9.17.10.4459
https://www.catalog.update.microsoft.com/Search.aspx?q=HD%203000
Broadcom BCM2045B USB Bluetooth Module (Install manually) 6.5.1.6820
https://www.catalog.update.microsoft.com/Search.aspx?q=usb%20to%20bluetooth
DO NOT USE 12.x.x.x, those are for Bluetooth 4.0
Conexant 20672 (Sound) 8.32.43.0
https://support.lenovo.com/gr/en/downloads/ds032124
Conexant 11270 (Modem) 7.80.8.50
https://support.lenovo.com/us/en/downloads/ds013944
nVidia 4200m (perpetually updates) 392.37 Can also use GForce GT520M drivers.
https://www.nvidia.com/Download/driverResults.aspx/143113/en-us
Better ICC Profile
Smart Card Reader 4.1.0.1 Untested, it's not on my model
https://support.lenovo.com/us/en/downloads/ds014067
Note1: ThinkPadFanControl is needed to get full speed out of the fan, which the T420 won't do on its own.
Use with caution -- the settings I list give plenty of leeway.
Note2: TPFC - USE v063 for the T420
Note2: I set up Throttlestop to still allow thermal throttling for safety, but only down to 2G instead of the useless 0.8G
ThinkPadFanControl
USE v063 for T420
https://thinkwiki.de/TPFanControl
ThrottleStop 8.70.6
https://www.techpowerup.com/download/techpowerup-throttlestop/
MSI Afterburner (underclock to reduce heat because everything shares a heatsink or overclock to get that extra 2FPS)
I've been stable @ 900/1800/1000 for well over a couple of years.
https://www.msi.com/page/afterburner
My TPFanControl.ini
https://www.dropbox.com/s/tre37i4zmfw57fe/TPFanControl.ini?dl=0
My ThrottleStop settings
https://www.dropbox.com/s/doqy5yjcsi7ror1/ThrottleStop.ini?dl=0
The chipset drivers above seem to work fine, if you like you can manually update the following. (Go to Device Manager and use the 'Search Automatically' option. For some reason Intel now Unix-dates their chipset drivers to 1969 so they won't over-ride existing drivers -- this is the work-around.
At the time of writing, the version for these is 10.1.1.38
2nd generation Intel(R) Core(TM) processor family DRAM Controller - 0104
Intel(R) 6 Series/C200 Series Chipset Family USB Enhanced Host Controller - 1C26
Intel(R) 6 Series/C200 Series Chipset Family USB Enhanced Host Controller - 1C2D
Intel(R) QM67 Express Chipset Family LPC Interface Controller - 1C4F
2nd generation Intel(R) Core(TM) processor family PCI Express Controller - 0101
Intel(R) 6 Series/C200 Series Chipset Family PCI Express Root Port 1 - 1C10
Intel(R) 6 Series/C200 Series Chipset Family PCI Express Root Port 2 - 1C12
Intel(R) 6 Series/C200 Series Chipset Family PCI Express Root Port 4 - 1C16
Intel(R) 6 Series/C200 Series Chipset Family PCI Express Root Port 5 - 1C18
Intel(R) 6 Series/C200 Series Chipset Family SMBus Controller - 1C22
Note: The LTHMD is mainly for fixing your serial number in BIOS after hardware replacement.
T420/T420i User Guide
https://download.lenovo.com/pccbbs/mobiles_pdf/t420_and_t420i_ug_en.pdf
T420/T420i Maintenance Manual
https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/t420_t420i_hmm.pdf
Lenovo Battery Firmware Update 1.16
https://support.lenovo.com/us/en/downloads/ds001322
Lenovo Keyboard Test 4.7.0.8081
https://support.lenovo.com/us/en/downloads/ds112679
The elusive Lenovo Thinkpad Hardware Maintenance Diskette v1.9 (this one works from W10)
http://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles/i7tm38us.exe
OEM Info (.reg file) and various OEMLogo.bmp files
https://www.dropbox.com/s/9l0aqd4t1221z69/OEM%20Info%20%2B%20Icons.rar?dl=0
Because things randomly disappear or get moved off the Lenovo Site so the links above may break at any time,
I have the files mirrored via Dropbox, but renamed to useful things instead of Lenovo's random number scheme.
Note1: Throttlestop and nVidia drivers update frequently, so those particular files might be out of date.
Note2: Guaranteed Virus Free because I wouldn't be enough of a dipshit to have viruses infesting my dropbox folder.
Note3: This is some random-ass website, you'll just have to take my word as a fellow T420 enthusiast that I understand the
pain of wading through Lenovo's/Intel's/Microsoft's sites trying to find current versions of things and hoping the W7
versions work in W10, so I'm doing this to share you some trouble rather than screw with you.
Note4: All the software is currently installed on my own T420, and with the exception of the buggy Ricoh card reader
and Window's tendency to fuck with the camera drivers, everything else should work just fine.
https://www.dropbox.com/sh/52058f3ewi1scpd/AADaW8QJbgR_Th1kNxl708E9a?dl=0