Hard drives get alot of bad press and for good reason, but on the macbook pro for example it is sometimes the fault of the cable that connects to the motherboard or the (logic board) that apple like to call it. This is overlooked quite alot of the time by apple technicians. Guys that fix apple stuff will 100% know about this fault.
Once this is replaced you can just connect the drive up and everything will just work as normal.
Lets have a look at what im talking about .....
Standard macbook pro, A1278 in for data recovery
Look for this number on the base of the macbook pro this one is a A1278
A macbook pro with the base off it , the hitachi HTS545050B9A302 500GB hard drive is very common on the macbook pro but thats not important right now. we are interested in the cable, lets see what it looks like.
Here we see the hard drive cable that connects to the motherboard / logic board. This is the part that can sometimes be at fault. Only real way to test this is to replace it. They are not expensive.
The faulty cable removed from the macbook pro, its a bit tricky to get in and out but its not overly complicated. Any good technician could do it
Find the model of macbook pro from the base and then put it into ebay and look for the corresponding cable that suits the potentially faulty model.
Connect back up the hard drive, put the base back on and give it a try. If that didn't work then it may be the hard drive after all. If it is then give me a call on 0141 237 1008