Recently on a trip i was using my pentax optio s and i wanted to conserve battery life; so i turned off the display, but after taking a few shot i wanted to see the picture and the display wouldn't turn on so i turned off the camera and turned it back on and the display showed a "A90" error. so i downloaded the firmware and tried to installing it in the camera. But after i had reformated the sd card ( i did this with the usb connected with the pc and camera) and tried holding the "menu + flash icon + power button" to get to the "secret menu" the green light surrounding power button just keeps on flashing on and off. The display doesn't show anything the lens doesn't open or do anything, all i get it the light flashing. i've tried removing the battery and putting the battery fully charged back in and the light still flash, i've tried holding on the power button for a while and nothing happen. my camera is about 4 years old and i've dropped it once about 4 or 5 months after i bought it but it worked fine without a problem for about 3 1/2 years. Have any one experience this problem or have a solution or could tell me what's wrong with it? thanks in advance!