I'm home sick with the flu so I thought I would use the time to start work on a MacBook that I bought that from eBay. The seller described a common problem where the MacBook would think it was on when the lid was closed and when the lid was opened, it would shut off. I thought it sounded like a PRAM battery problem which I could easily fix. While I was waiting for the new PRAM battery, I installed my own hard drive from an old Windows laptop that I used Disk Utility to format and installed Yosemite successfully. I also bought a new battery, power adapter and upgraded the RAM to 4GB. Before the new PRAM battery came I ran into an issue where once the computer was shut off, it has difficulty starting again. When I depress the power button, I can hear the hard drive spinning, but there is no further boot activity. No start up chime and nothing on the screen. Just the hard drive spinning. I've tried an SMC reset and also a trick to bypass the SMC by plugging in the Magsafe whilst holding the power button. No luck. I feel like if I could get the computer to boot and reset the PRAM with the new PRAM battery, there is a chance that all could be well, but without a proper boot up with the start up chime, I'm dead in the water. I'd really like to get this computer running so any and all advice or recommendations the community has would be greatly appreciated.