First, just to rule out a corrupt file system, format the hard drive if you have not already done so. I would also recommend checking the warranty on the DVD recorder in case it is still within its warranty, particularly if it is under a year old as this would at least save the cost of getting a new HD if so.
The replacement hard drive should match the size of the one being replaced (unless someone here can confirm larger / smaller HD's also work). Most DVD recorders will automatically partition and create a file system if a new hard drive is installed. However if this is not the case, you will need to recover what's on the faulty HD or get a copy off someone else who also has the same model. :rolleyes:
Hopefully someone here can give advice on how easily this can be done as so far I haven't actually change a hard drive in a Pansonic.