My Inspiron 1525 is giving me the message "No bootable devices....."

My laptop crashed about two years ago and I took it to a computer store down the street. They originally told me that my hard drive needed to be replaced. After I agreed for them to replace the hard drive, they then told me my processor was bad and my laptop could not be repaired. My questions are: would a faulty processor and an over used hard drive show the same symptoms and also if I was to send my computer back to Dell for a new hard drive and it is discovered that I truly do have a faulty processor, what would I be charged for?