As far as I have ever seen reported DV or HDV data capture into Premiere Elements Capture Windows (any version) does not work unless the connection is firewire. And, there are occasions (especially with HDV capture firewire) the require that the capture firewire be done in HDVSplit and then the split clips imported into a Premiere Elements project via the typical Get Media/Add Media route.
Which version of Premiere Elements allowed you to do a DV or HDV capture firewire in to its Capture Window using a USB connection? From what you wrote it gave me the impression that you were saying that you had.
If you have followed the protocol for HDV data capture firewire into Premiere Elements 12 (with correct project preset)
then you would need to explore the use of HDVSplit (firewire connection) and then import of the .m2t split clips from that process in to Premiere Elements 12 (Add Media/Files and Folders/Project Assets).
If both these Canon camera are miniDV camcorders, then you need a firewire connect to the data capture into Premiere Elements Capture Windows.
Do you have access to a computer with a firewire port?
Does your computer have what is referred to as a PCMCIA slot for use with a firewire card? Have you looked into the possibility? No sure if that will work for you.
Says Premiere Pro, but steps are similar for Premiere Elements
-and Windows http://forums.adobe.com/message/4708997
>changed the USB connecting cable
As already said, Firewire only for a tape camera
HDV Split et all are fine. But, I have never heard that done without a firewire connection which seems to be at the root of your issue with your miniDV camcorders.
Also, I would remind you that it seems prudent first to use information specific to the program that you are using and then, if absolutely necessary, consider steps similar in other programs which are not yours. This is especially indicated when information is available for your own program as is the case here.