@adriananlam52581 I don't think this is an issue related to your HDD or the connector. This sounds like corrupted SPI serial flash. You could contact Lenovo to possibly have them reflash the BIOS or see if you can find a replacement BIOS Flash IC. Pre Programmed Bios chip are available online, but will require some board level soldering.
Of course and if nothing else, try to install a different OS like Linux. See if that will get your computer at least to boot.
Here is the schematic [document|29457] for your Y50-70 (should be a Compal LA-B111 but you want to verify this of course) and here is the location of the BIOS
[image|2997927]