Agreed. Also, the longer replacement cable from Eutronix might be a good idea as well. Less tension on the drive cable and header.

Is this something I can fit myself (without soldering) .. ?

Yes. There are 40/44 (I forget) pin plugs at each end. The cable is secured on the harddrive with hot melt glue, so be sure to pry/peel that off before trying to pull off the connector.

While you have the connector off from the IDE header at the motherboard, check the soldering of the pins. If iffy, have someone good at soldering go over them.

/Michael