# TSG: Pen display turns on and off constantly

## Symptoms

In this situation, when your pen display is plugged in you may see something shown on the screen for a moment, then nothing is shown on the screen for a moment, then it cycles and shows something on the screen again. This cycling will go on forever.

When it is on you may see that the screen is just showing a field of a solid white color. Or you may see a brand logo or some other indication that the display panel is actually working.

## Primary causes

### Pen display not getting enough power

Overwhelmingly the primary cause of this cycling seems to be that the pen display is not getting enough power.

If you're connecting through a three-in-one cable, make sure that the power is coming from an AC adapter instead of from a computer. Often computers can't deliver enough power, especially when the pen display is larger than 13 inches.

If you are connecting via USB C cable, then try a different port because maybe it will supply enough power. Or you may have to switch to using a three in one cable.

## Potential but rarer causes

### Ambient heat

I've encountered a situation where someone's pen display performed this power cycling - but it was not due to being underpowered. It was related to how warm the pen display was getting due to the current weather conditions. See: [r/huion - Help\] Kamvas 13 turning on and off repeatedly](https://www.reddit.com/r/huion/comments/1fzfihm/help_kamvas_13_turning_on_and_off_repeatedly/).

This is EXTREMELY rare and I suspect linked to a defect in that specific tablet. It is not something to expect from a tablet.


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