I have a single HP EliteDisplay E243i that I use as an external monitor for my Macbook Pro (2023) and Lenovo Thinkpad to extend their screens, not at the same time. The monitor was working (displaying my laptop screen properly), then I unplugged the HDMI cable from Macbook to E243i so I could plug my Macbook to my TV using the same HDMI cable, which worked. When I connected either the Macbook or Thinkpad back to the E243i, the E243i shows a popup saying HDMI is "Inactive" (when it worked, it said "Active"), and then just a black screen. Notes:
- Both my Macbook and Thinkpad detect that the E243i is connected.
- E243i is set to input HDMI.
- I've tried factory reset on E243i.
- I'm not sure what happened between the E243i working and me initially unplugging it, then plugging back in that caused the problem.
- In case the cause is dust, I've tried blowing the HDMI cable, HDMI port on monitor, and HDMI port on laptops.
- Since connecting Macbook to my TV using the same HDMI cable works, and both my Macbook and Thinkpad detect the E243i, I think the issue is probably with the E243i, but I don't know what.
- I didn't find any relevant drivers at https://support.hp.com/us-en/drivers/hp-elitedisplay-e243i-24-inch-monitor/17210318
Anything else I should try?