How to troubleshoot miracast on windows 10 laptop?

Solution 1:

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.