Dojj, First off do not do this as this will more than likely destroy the drive and any cheap or easy way of getting the data off the drive. As you have tried fitting it to another machine and it has the same problem the drive may be faulty. All you can do is try fitting it internally to another pc and hope.

A data recovery company will be able to retrieve the data for you although this will not be cheap, for approx 10GB of data expect to pay from £700 upwards. My firm had to send away 5 drives for this service that where badly damaged and paid £3000+ for the data.