Reflashing an XO-1.5 using a USB drive prepared for an XO-1 should be harmless and ineffective. Yes, it will tell you to power off.
Now, it sounds like the mechanical vibrations of you doing this has caused the #10314 bricking [1]; black screen, power light on, nothing else ... but to be sure I'd have to check the serial number. I know how to fix it; replace the motherboard, or reflow the solder under the CPU. But don't try it unless you know how to do it. Good to find out now rather than when a child has it. References: 1. http://dev.laptop.org/ticket/10314 -- James Cameron http://quozl.linux.org.au/ _______________________________________________ IAEP -- It's An Education Project (not a laptop project!) IAEP@lists.sugarlabs.org http://lists.sugarlabs.org/listinfo/iaep