Why are my WD Hard drives not compatible with my TV/DVD player

I have 6 Terabyte hard drives, 5 of which are Western Digital (3 different models). My 6th one is Iomega. I use them all for Media Storage for Movies, Music and TV shows. For some reason I can plug the Iomega up to a Play Station, TV, DVD player anything with a USB port and the play all the Avi files fine. Any time I hook any of my Western Digital Hard drives up to anything ither than a computer they do not work. They recognize something is there but say there is no information stored or that it can not access it. Can anyone tell me why, or perhaps even tell me how to fix the problem other than buying another brand??

Needs to be formatted for FAT32.

http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1364&p_created=1117047065&p_sid=WT9wHBRj&p_accessibility=0&p_redirect=&p_srch=1&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9NDksNDkmcF9wcm9kcz0mcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PUZBVDMy&p_li=&p_topview=1

Thank you, I am not sure that this will work yet but it gives me a place to start. I see it says hard drives before 2007, but all of my WD hard drives have been purchased within the last year. I have only recently gotten into storing all of my media rather than keeping them on the disks. I am working in Iraq so I have to limit how much I travel with: thus all the externals. I’ll let you know when I figure out if it is going to work for them.

Thanks