Recovering data from broken iPhone is really difficult. If you have backed up your iPhone with iTunes, you can try to get all data back from iTunes backup. If you have backed up you iPhone, some data recovery software may help you. I have read an article about recover data from dead or broken...
If you are missing files from folders on your external hard drive. I personally suggest you try Any Data Recovery Pro. With it, you can easily recover data from your external hard drive. Not only external hard drive, this software has the capability to recover any kind of data from any PCs...