Hard drive error at boot

Hi everyone. I have a strange problem I have never come across before. I had a laptop in my shop that needed a power connector soldered back to the board. That went fine. No when you boot up before you can even get to windows you get a screen that says the hard drive is locked. Don't have any passwords that work and when you go into bios and change the settings back to defalt it will let you boot up untill you turn it off and restart. You will get the hard drive locked again. There is a setting in the bios for applying a hdd password. But no one put one on it. Why would it suddenly ask for a password?? Any help would be greatly appreciated.