A Windows update a couple of weeks ago broke miracast on my laptop (Dell XPS13 9350 / i7-6560U / Iris 540). It broke on v1703, and the v1709 update did not fix it. My machine automatically installs all updates from Microsoft.
I depend on miracast, at home and work, and this has been pretty painful.
I know I can uninstall updates until I find the culprit (per How uninstall Win 10 update? (it broke my miracast) ), but I am more curious: How can I diagnose/troubleshoot miracast?
The symptom is:
My laptop sees the miracast display, and attempts to connect, but fails.
Sometimes it does connect, and it works for some minutes, before the entire wifi connection drops, losing inet and miracast in process.
In all cases I am using the microsoft hdmi dongle as the miracast receiver.
I know the problem is my laptop because:
1) Other laptops can connect to these same miracast receivers with no problem.
2) My laptop has the exact same problems across three different miracast receivers.
3) Before the updates, my laptop had no problems with any miracast receier
4) Installing “Feature update to Windows 10, version 1709” did not help at all.
I see multiple reports of this issue:
- https://answers.microsoft.com/en-us/windows/forum/windows_10-hardware/fall-creators-update-broke-miracast-including/2b02ae90-950f-41a0-ba72-e04cf6c7b1e1?auth=1
- https://answers.microsoft.com/en-us/windows/forum/windows_10-win_continuum/miracast-broken-after-fall-creators-update/fd3e432a-358a-48bc-a860-5ae5f5bc7e9e
So, now that we have cooked it down, what do I do next to resolve properly?
Solution:
It appears I have found a solution.
The wifi interface in this laptop is the Broadcom 1820A
I looked at the driver, and it was 1.566.0.2, from October 2017.
In one of the threads I had opened with Microsoft on this issue, they had suggested going back to earlier driver versions, but at that time, I did not see how or why.
My desperation to resolve this issue, however, has grown.
Today, I tried something new. I simply googled “broadcom 1820a driver”
This brought me to this Dell driver download page, which has the 1.566.0.1 version of the driver, from earlier in 2017.
As the problem started in November 2017, after a driver update, the October driver version is, in fact, suspect.
I uninstalled the 1.566.0.2 driver, installed 1.566.0.1 (no reboots required, though all wifi passwords are forgotten), and voila. I seem to have working miracast.
There are tears in my eyes. I so missed miracast (and cursed the return to dongles and hdmi cables).
UPDATE AUGUST 6, 2019
The recent win10 update caused most or all drivers to update, and the problem is back.
After using the Dell update tool to update all drivers, the problem seems resolved.
UPDATE DECEMBER 19, 2019
(Apologies for delay)
Nope.
The August 6 2019 update above did NOT resolve. Miracast will work for 5-20 minutes, then fail completely and only recover after full reboot. Other Windows 10 laptops on same display rig can miracast for hours.
Problem now seems to be that the wifi interface in this model laptop is the root problem.