My headshot

Ben Potter

Fixing "Input Not Support" on an AOC E2070S on macOS

July 8, 2026

I used an AOC E2070S (a 20-inch, 1600x900 monitor) as a second screen for a couple of weeks. Plugged into a Mac, it kept showing "Input Not Support" on the OSD (that's the exact wording the monitor uses). Sometimes the screen was black, sometimes it flashed the error and gave up.

This isn't a great fix, but it got me through two weeks, so I'm writing it down in case it helps someone.

The workaround

I used BetterDisplay, which can talk to the monitor over DDC.

  1. Install BetterDisplay and open it.
  2. Find the E2070S in the display list.
  3. Run "Detect DDC capabilities".
  4. Then run "Auto-configure DDC features".
  5. Set the resolution to 1600x900 and leave it there.

After that the monitor accepted the signal. Once it's at 1600x900 it mostly stays working.

When it comes back

The error would sometimes return, usually after sleep or unplugging. What fixed it for me was adjusting the brightness in BetterDisplay by a notch. That was enough to get the picture back.

I don't know exactly why that works, but it was reliable enough that I stopped worrying about it.

Is this a good fix?

Not really. It's a workaround for an old, cheap monitor. If this were a permanent setup I'd just use a different monitor. But for a temporary second screen it was fine.

Hope it helps someone.