The tale of two T420s and Intel AC 7260\Bluetooth and Pin 51 tape

[ji2o0k]

Hoping someone can help explain this to me...

I have two Lenovo T420s (details below). Both are set up very similarily. Both have whitelisted BIOS and I installed the Intel AC7260 + bluetooth Wifi cards. One that had a stock BT worked flawlessly after I installed the AC 7260 card...no issues (I disabled the stock BT adapter and only have the AC7260 BT enabled).

The one without stock BT had issues and I finally stumbled by accident the Pin 51 tape trick. Now everything works flawlessly after taping PIN 51 on the card.

Details below:
Card I am using in both T420s: Intel Dual Band Wireless-AC 7260 2x2 Network plus Bluetooth adapter (7260.HMWWB.R)

PIN 51 tape solution I stumbled upon: https://www.youtube.com/watch?v=F_OWzdeNmD8

1. Lenovo T420s i5 <- this T420s worked right after installing the AC7260 wifi + BT card
Type 4171-53U
Came with stock Bluetooth (I can tell as the BT indicator lights up on the screen bezel)
Disabled the stock BT and everything works well.

2. Lenovo T420s i7 <- this is the T420s that BT didn't work after installing the AC7260 wifi card until I taped PIN 51
Type 4170-CTO
Did not come with Bluetooth (no BT indicator light on screen bezel)

I did install the latest Intel Pro Wireless software package as well as the Intel BT software - but still no dice on T420s #2 - I originally saw the BT in Device Manager but it disappeared after...

Any ideas?

P.S. Forgot to add that both have Bluetooth enabled in BIOS (i.e. Security - IO Port Access)

[gobaers]

For the T420s, you shouldn't need to tape the pin, just flash the de-whitelisted bios.

[ji2o0k]

For the T420s, you shouldn't need to tape the pin, just flash the de-whitelisted bios.

Weird....both had the same whitelist bios loaded but I couldn't get BT working without taping PIN 51 on the other one.

Whelp, it is working now and will leave it...chalk it up to a mystery...lol

Thx for the help!

[rkan]

I'm chiming in with similar issues, altough I've yet to tape pin 51, because I have not had to before. I've had my X220 with AC7260 for two years now, and both wifi and Bluetooth were working without issues until about couple of months ago. Now it seems only wifi is working. I did disassemble the computer once in between, and also might have reversed the antenna connections, which in my opinion shouldn't have anything to do with it. I am going to report back when I get the pin 51 taped! I think I was running a whitelisted 1.42 BIOS. (I'll check that too)

edit: Nevermind, it was the pin 51 tape that had come loose... All good now as usual. Perhaps the pin 51 was just broken on the other T420 / AC7260?

[Sweater Fish Deluxe]

Can someone clarify for me what's up with the USB lines on the mPCIe ports of the T420s?

The bluetooth daughtercard in my T420s is no longer working and I've already tried putting in a new daughtercard with no luck and also already have an mSATA drive in my WWAN slot, so getting bluetooth working on a combo card in the WLAN slot seems to be my next choice.

The thing is, I thought I understood that the half-size WLAN slot on these machines was PCIe-only and doesn't even carry the USB connections needed for the bluetooth part of a wifi+bluetooth combo adapter. Am I just wrong? I've never tested a combo adapter myself, but I have tested other USB mPCIe devices in that slot and they did not work. These were a microSD card reader and a mPCIe form factor USB wifi card from Realtek, both of which I have tested in other mPCIe slots that do have the USB lines (including my T420s' WWAN slot), so I know they are not broken.

Do all USB devices in this slot need to have pin 51 taped even if they don't have a bluetooth radio? Or is there actually some kind of variation in the USB connection on this slot?

[uni_0n]

sorry for answering after 100 years
this problem walking on some laptops of the last decade is not a joke at all and quite weird

after disassembling and assembling my t440p again, due to the repair of the usb port, this problem also got me
purely after interest I tried to cover pins 54 and 56 on my Intel Wireless AC 7260 (m.2 slot) and I did not at all expect that the Bluetooth appeared back in the task manager.
what i haven't done anything before solution, trust me.

what kind of topic is this with those "painful" cards from Intel and pin tricks?

software solutions, as I understand it, do not exist?
in addition to the bios flashing
maybe it's ok to live with this, I just don’t like to “handmade repair” my laptop because of poor engineers and programmers once again

source: thecomputerperson.wordpress.com/2016/11/04/how-to-mask-off-the-wifi-power-off-pins-on-m-2-ngff-wireless-cards-the-old-mini-pci-pin-20-trick/

[RealBlackStuff]

My T440p (with AC-7260) does not show Bluetooth in Device Manager either.
BUT...
Only because I have it disabled in the BIOS!

[uni_0n]

It seems to me that I was able to overcome this problem of engineers! No matter which ones
No, I'm not a computer genius
I killed a couple of days of my life.
The bluetooth and fingerprint scanner just disappeared from Device Manager after hibernation mode.
Me and my laptop needs to take a break finally.
I hope that there will be no further problems with these darn m.2 WiFi cards from Intel.
My ThinkPad T440p has an Intel Wireless AC 7260NGW (FRU: 04X6007) card installed.
May be useful to someone.
No, this is not nonsense, truly real story and experience.

What i did (maybe some of the steps look unnecessary, I wouldn't say so):
1. Covered/taped pins 54 and 56.
You can find link to the source site with a photo of pins location is to the message(s) above
2. Reconnected the BIOS battery.
I know that was only clock reset, a habit?
3. Installed an drive (GPT-parted) from another laptop (i took it form TP L440) with the latest Windows 10.
You can also do a clean installation on an empty disk too, this Windows will be just temporary.
Do not forget to disable Secure Boot in BIOS if you have problems with the boot.
4. Latest drivers with OEM software (desirable), latest BIOS and extra Model Number update.
It's important not to forget the hotkey driver.
5. Latest drivers in Lenovo Vantage.
Make sure Intel ME got the firmware update too, which was in my case.
6. Several reboots, sleeps and hibernations to make sure that everything is working successfully without falling away.
I did not switch anything in the BIOS, everything is on.
7. Put back the drive with main Windows 10/11 (I have 11, it's a secret )
8. Several reboots, sleeps and hibernations again to make sure that everything is working peacefully.
9. Uncovered pins on the WiFi card and again repeat steps at number 7.

> After that everything worked for me and WiFi switch (F8) too.
> Throughout the process, the device power saving settings in Device Manager were enabled by default (not the culprit).
> For relaxation, you can drive various scans of Windows System Files etc.
Actually I did not forget about the colors of the antennas on the contrary. More than enough happy with the speeds.