K10D display not working

I have a K10D that I turned on one day and the display stopped working. It is completely black-It won't playback or show any info whatsoever. When I hit the play button, the orange light on the bottom right lights up, but nothing happens. I have tried new batteries and a new card. I also tried changing the lens. Please help!

You could try re-installing the firmware again see if that helps. Get it from HERE.
What happens when you check firmware version? Just hold down the menu button then turn it on, it SHOULD display the version number in the middle of the screen, Ver 1.30 or something should appear.

Hope this help!

I know this may be a really daft question, but were you wearing glasses at the time? I once had the same thing before realising my polarised glasses were preventing me from seeing anything on the screen, even though the camera was fine.

I know what you mean about the polarized lenses, but I wasn't wearing them.

I tried checking the firmware, but the screen won't even show me that.

Low battery as in this thread -
http://www.pentaxforums.com/forums/pentax-dslr-discussion/94026-k10d-back-displa...
This has references to the problem being caused by a defective memory card, or the memory card door not properly shut -
http://www.fixya.com/support/t209535-pentax_k10d_both_lcd_screens_blank

Ehow says - "lso, some people experienced their camera freezing up after a lens change or a memory-card replacement, and had to send their camera back to Pentax for repair."

Sounds like you have tried most of the above. Memory card door closed?

Good luck, hope you get it sorted.

Paul