# DIAG: Checking if pen display shows HDMI video signal from other devices
## Overview
Among other things that a pen display receives from your computer, it also receives a "display signal". Display signal means essentially "video" - what you see on the pen display.
Normally your pen display will be connected to your computer, which provides a display signal via an HDMI connection.
But your pen display can receive that display signal from any device that supports a display signal. For example an Xbox, PlayStation, a DVD player, another computer, and even some mirrorless cameras (example Sony FX30).
This is useful for several reasons.
\- It allows your pen display to be used like a monitor or TV
\- it's also a good troubleshooting technique
## Troubleshooting
If you're getting problems like one of these:
\- Not seeing anything
\- Odd Flickering
\- Weird colors
\- "No Signal"
Then connecting your pen display via HDMI to another device is a very useful technique, because it gives you a hint as to whether the problem is with the tablet itself or with your computer.
If one device does not work, try others.
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