Why won't my Z10 turn on?

My Z10 shut off few days ago. Tried to turn on using the power button. Red light comes on, and stays on for about one minute, then goes off; the screen stay black.

Tried holding the power button for 10 seconds, red light blinks, then comes on as described above.

Tried another battery, same result.

Tried connecting to BlackBerry Link without a battery, red light came on and off after a minute, just the same.

BlackberryLink won't recognize device is connected; tried reloading the OS anyway, it won't do it because it thinks there is no device connected.

Any other suggestions?

Thanks.

You have to search on the google : blackberry 10 updates then press on the blackberry 10 software updates then press check for updates to download the autoloader

Posted via CB10

I downloaded (Autoload-STL100-3-10.2.1.1927), removed battery, and connected the phone to my laptop using USB cable; the red light came on, just like before. Started the autoloader, it seems stuck at "Connecting to Bootrom". The red light went off after a minute or so. Autoloader still waiting to connect to bootrom.

Tried with the battery, same result.

Have no sim or sdcard in the phone.