Hey Bingrd,
Thank you for visiting the HP Support Forums and Welcome. I have read your thread on your HP Pavilion Notebook and issues with the HDD. Here is a link to computer won't start. The section needed is led glow, fan noise is heard, but display is black or blank. Please note remove any and all USB devices, and remove memory cards from the card reader slot. Disconnect all non-essential devices. You could try a hardware test.
Hope this helps.
Thanks.