Upgrade from firmware v1.50 to v1.52 failed and now the Espruino board seems dead

I tried to press and hold the BTN1 before power on (from a 5.25v battery) , after power on the red and blue LED on board will be turned on at a full light. Press Reset button then they darker to about 20% power.

Good news,

1. Connect to computer through the micro USB cable. Computer can't see it.
   
2. When the red and blue LED are darker, press and hold BTN1 and then press Reset then the host computer sounds! (USB connected sound). Then the red LED turned off and the blue LED start glowing. Now the COM3 appears on the Web IDE.
   
3. So I am back now at the upgrade process step 4. A little problem is the v1.52 firmware's .bin file URL is not automatically shown. Where is it? ..... Ah, it's in http://www.espruino.com/binaries/
   
4. So I go on finish the upgrading process and voila! ok now.
   
   

Wow, very robust bro! Thank God.