Hi there BOYCIE48,
I believe that the best thing you can do is to contact the TV's support for that. Maybe the guys over there should be able to help out.
Apart from that, you can go to Disk Management and see what is the file system of the drive:
http
/products.wdc.com/support/kb.ashx?id=LtHfeT
I believe the TV should support NTFS.
Also, some file formats may not be supported by it. Try to transfer some other file formats to the drive, except for mp4 and see if they would be recognized by the TV.
Is the drive the only attached device to the TV?
What is its capacity? Some TVs have limitations on the maximum storage capacity of the external drives attached. In case you have a smaller drive(or a USB flash drive), you can try that...