PS3 YLOD Issue...

So basically my 80 GB PS3 got the YLOD a while ago. When I turn it on, the light turns green, then yellow, then keeps flashing red. It has been upgraded to a 320 GB HD. Im planning on sending it in to sony but Im pretty sure their are things I haven't backed up and now I can't because the PS3 wont turn on. If I send it to Sony am I going to lose everything on the HD? Also, I have the original 80 GB HD still, if that helps.

My ps3 currently died on me 3 days ago.. it got the YLOD.. 80GB Motorstorm edition.. i took care of it, dusted it off whenever i saw dust on it, it was kept in a well ventilated area. The way i see it Sony sucks ass.. and i called Sonys CustomerService line and they're telling me i got to pay $202.27CDN to get it repaired. might as well buy a new one and put the HDD on that one.