Put in the latest firmware on my Olympus EP-3 today but camera won't turn on now. Is there any recovery procedure or do I have to send the camera in for service?
I'd try to upload the firmware a second time. Just in case it works. I find the Olympus updates rather tricky. Instead of downloading the firmware update and copying it to the SD card, you have to hook the camera directly, which is tedious because it takes a long time and the lcd remains blacked out without telling anything for way too long.
Then, when the warning telling that you should wait for the OK sign without touching any button. it doesn't even last as long as the blacked out lcd before. I find this behaviour weird and a possible source of confusion for people lacking the patience. I've been tempted to stop the process many times, but happily didn't and never got a problem.
Anyway, before sending the camera back, which is a hassle, I'd try to redo the operation another time, but wait a long time before doing anything with the buttons and use a full loaded battery.
Good luck