My external hard drive is not detected in *SOME* ports

Hmmm. OK. but wouldn’t that be solved by the other usb plug? the main USB plug has another one sticking out. isn’t it supposed to provide power? and how come my other external hard drives don’t experience this? (including a really old 75gb one, which was extremely huge during the time i bought it. the current one that’s having problems is 320gb wd3200me. i am also not having problems with my other 1tb and 500gb external portable hard drives. (all of which are WD, except for the 75gb one.