Sometimes no Display on TV when connected to HDMI

i have a generation 4 iPad with iOS 8

I connect the iPad to my tv using and HDMI cord and the adapter. Occasionally, the iPad will not display on the tv when plugged in. It seems to recognize that it's plugged in because the bar on the top lights up blue like it's plugged in and the TV recognizes that something is plugged in because when it's unplugged the TV says no input and when the iPad is plugged in the no input signal Disappears. however there is no display on the TV.

Now, when I turn the iPad all the way off, power it down, and then power it back up the display will show. But I don't know why it doesn't show up in the first place.

Any ideas?

thanks