Kad are these new cables or used? Even if used, they've been idle for awhile so you still need to allow for some breakin time, but if new then you really need to cook them at high power levels for awhile before drawing any conclusions. Run them for 100 to 200 hours at higher power levels when no one is home (DO be considerate if you have pets!). Several threads on breakin are existing here for your perusal.
