My original Pentax Q also died and for several months wouldn't turn on or give any signs of life.
I hadn't use it for several months and when I tried to turn it on it would not start. If I remember correctly, it turn on once and for some reason I've turn it off and back on again and didn't turn on anymore.
First I thought the battery was dead. I've test it with a multimeter and it looked OK.
I've bought and tried with a new battery and still nothing.
For the next three or four months I've tried to turn it on three or four times a week with no success. Not knowing what else to try I've tried to heat up the camera and the battery with a hair dryer. Separately! Yes, it sounds desperate. I don't remember what made me do it. Maybe I thought that it might be moister.
I have never let the camera get screaming hot but it was clearly warm to the touch. Also, beware that lithium batteries don't like to get to hot.
(Edit: When heating the camera I took the lens out!)
I had to do it more than once but not to many times. If I remember correctly the camera turn on on the second attempt, maybe third. I was completely surprised.
After that every time I changed battery the camera would loose the date and time settings. This made me believe that the problem relates with the internal battery that keeps these settings. Lithium batteries cut off power when their voltage gets to low. Maybe this left the internal battery with no way of charging itself. And maybe the internal battery has also something to do with the camera boot procedure or boot settings?
I've tried to change batteries as quickly as possible and I've also tried to change SD cards as someone in the forum suggests but nothing worked. I thought that I would have to live with that 'bug' but I was happy that at least the camera worked.
Fortunately, after a month or so even this issue disappeared! Maybe the internal battery slowly recovered and was able to keep some charge? Who knows?
Since then I always make sure that the Q battery is fully charged even when I'm not using it.
That's it, hope this can help you.
Vitor
Last edited by Zelig; 04-14-2016 at 04:54 AM.