How can I get my MK808 mini Android PC to output to my TV? I had this mini pc from a friend. But I cannot power it up.

When I connect it to TV with HDMI cable, the light is blue, but I got nothing show on the TV screen. I've tried some different HDMI cables, but it will not put a picture out to the TV.

Can anyone suggest what the problem might be?
Its the resolution setting. That or your tv/monitor doesn't support the default setting. I was switching mine to all the different sizes and switched it to one my monitor didn't support. Was a total pain to switch back as I flipped it to some off size. Just try every tv/monitor you can find until it comes up. I have noted on a few occasions, it doesn't seem like its booting up right away, I had to unplug and wait a minute, then retry.