TL;DR: longstanding fingerprint scanner problem, fixed by reseating ribbon cable, and installing latest driver from MS update catalog (https://www.catalog.update.microsoft.com/Search.aspx?q=USB%5CVID_06CB%26PID_0081)
So I had an issue with the Synaptics WBDI fingprint scanner/reader in my Lenovo Yoga 720-13IKB (80X6). It first stopped working after a Windows 10 update, and then was patchy after a number of troubleshooting attempts, sometimes it would work for an hour, sometimes days, eventually it just stopped altogether. If you want to throw me into a depression spiral just say "Device can not start. (Code 10)".
Seriously, it took literally years to solve. I gave up more than a year ago. As of the last 30 minutes:
I'm posting here, because others out there may be afflicted with the same tormented thoughts and nightmares that I've had.
This godforsaken fingerprint reader, presumably identical hardware to that working perfectly in plenty laptops, was my white whale.
This post is
because I'll probably forget after reinstalling Windows and it'll drive me further insane in case it is your white whale too.
The original problem was discussed in here:
To my knowledge, the problem primarily affects Lenovo users, as Lenovo won't provide updated Synaptics drivers.
I happened to be doing some maintenance on my Yoga, and figured why not check for an update?
The old thread is locked.
Well, my curiosity had been awoken, and old mate Google came to the party, sending me here to a Lenovo Forum post:
Notice any similarities in the thread titles and content?
And... the original thread posting date.
Well, in that thread there is an update from August 2019, directing me to the MS update catalog (https://www.catalog.update.microsoft.com/)
Now, I'm not sure if everyone knew about this before, but I sure didn't.
I threw the offending device ID (which, horrifyingly, I had memorised) into the search field.
Would you just look at that... https://www.catalog.update.microsoft.com/Search.aspx?q=USB%5CVID_06CB%26PID_0081
Lenovo's "latest" driver: January 12, 2017 | Version 5.5.2603.1050
Microsoft Update catalog: June 5, 2019 | Version 5.5.2811.1050
Well, I'm not ashamed to tell you, I just about peed with excitement as I clicked download.
So here goes nothing:
1) Uninstalled device in Device Manager, removing the driver.
3) Installed the updated driver.
5) Device can not start. (Code 10)
THROW THE LAPTOP AGAINST TH-
6a) Re-read the latest post in the Lenovo Forum thread: "I unplugged and replugged the ribbon cable for the fingerprint sensor and now it works just fine."
7) Shut down Windows.
8) Open the laptop.
8a) Remember that you meant to read https://www.ifixit.com/Guide/Lenovo+Yoga+720+Fingerprint+Reader+Replacement/102477 first.
9) Remove the battery.
10) Unplug and re-seat the fingerprint reader ribbon cable.
11) Reconnect the battery.
12) Reassemble my laptop.
13) Boot into Windows.
14) Go to Windows Hello: ... We couldn't find a fingerprint scanner compatible with Windows Hello Fingerprint
15) Don't throw it.
16) I know you want to throw it, but don't do it.
17) Disable and re-enable the device in Device Manager.
18) Go to Windows Hello setup.
19) Sign in with your fingerprint scanner (Recommended)
21) Add fingerprints.
22) Log in with fingerprint.
I'm a happy Yoga user again.