HP Spectre x360 is causing external 4k monitor to pulse

[TGRedmond]

I just got this laptop and connected it to a new Samsung 4k monitor. The connection to the monitor is HDMI, and to the laptop/dock it uses the HP Thunderbolt-HDMI adapter. When connected to this laptop roughly every 3 seconds the monitor has a subtle bright flicker. This happens when connected directly to the laptop or via the dock. This did not appear during setup, or during the initial use, but started shortly after Windows completed updating and installing.

I have tried running the monitor at 1920x1080 30 Hz but the issue continues. Any suggestions?

[banhien]

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@TGRedmond wrote:

.... The connection to the monitor is HDMI, and to the laptop/dock it uses the HP Thunderbolt-HDMI adapter.

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@TGRedmond 

What is your HP Thunderbolt dock ? Is it compatible with your HP Spectre x360 machine ?

Regards.

[TGRedmond]

Thanks for responding.

The laptop model is  HP Spectre x360 Convertible 14t-ea200.

The dock is an HP Thunderbolt Dock G2 120w which was the one that was offered on the site when I ordered.

[TGRedmond]

I just did a quick check and eliminated both the dock and the external Samsung 4K monitor as the possible causes. When I connect the monitor directly to the Spectre using the Thunderbolt port to HDMI, it also pulses with a flicker every ~3-5 seconds. This does not occur when the external monitor is connected to two other laptops in the house - a Lenovo Carbon X1 and a Thinkpad. This reproduces immediately with the Spectre.