Pentax Q not turning on

Anyone else had a problem with the Q turning on ok then after switching it off it won't turn on again.
After a few hours it might turn on on and be fine then after switching it off it won't turn on again.
Very frustrating. It's had all the firmware updates but still has this problem

Are your batteries ok?

Yes, tried 3 different batteries, all fully charged, plus tried them in another Q