Hi,
Thanks for your reply, but as you said it is not relevant to my problem.
I never took out my microSD of the player while it it was on, and the problem didn't happen close to a time I swapped cards.
Other than that, with my experience with a number of flash drives types, it is highly un-recommended to remove a flash drive from a device while operating. Even if it is not reading or writing to a flash drive, a device may be operating some functions on the flash for maintenance (file system, cash writebacks, ware leveling, etc).
I think it probably an hardwere damage to the battery or memory, I hope I can get the warranty to replace it.
Thanks anyway