I disassembled my acer laptop to clean dust.since there was no dust i reassembled it without doing anything.now it won't turn on.when i plugges it into a/c it shows that the battery is been charged.(led is on) when i try to switch on the laptop without installing the battery nothing happens.is this a serious situation?do i have to go for a new laptop.my laptop model is acer aspire 5742-6874.