I have a very specific problem with using external hard disc case (with its own power source) which I tested on both ps2 and ps3. When I plug in the usb it in any playstation it works it read my games from fat32 partition but it interferes with the picture somehow (SDTV), it is not unbarable, but it is noticable and I am concerned that it could do some damage to the playstations (it is worse on ps2, since the interference is bigger).
It does not matter if the switch on the HDD case is off or on it still makes interference (slightly more when its on). I did extensive search but I could only find that some guys have similar problems on wii when they used external hdd case. Is it a problem with power somehow?
Any suggestions? I tested both usb ports on ps2 and ps3 slim, plugged it in different power sources and moved it as far away from the consoles as possible, it still makes the same problem the moment its usb cable is plugged into the console. Any ideas?