That looks like the kind of connector which has a little catch (for want of a better word) that should sit around the connector on the motherboard - getting a new cable won't help. Normally beige or cream in colour, looks something like a flat U or I_I. When its pushed down it will hold the cable in place and ensure proper contact between the data cable and motherboard.
Doesn't look like you have it - did you notice anything fall out when you opened the flap on the bottom? Am pretty sure you won't be able to find a replacement part. Somebody might have a bright idea where they've encountered similar? Or, if your laptop support it, get an external caddy for the drive for a few quid and you could boot from USB.