On Panasonic VCR's these symptoms are often due to tooth damage to the plastic gears underneath side of mechanism.
Z-Mechanism: Approx 2002-2004 - check Left Side Loading Gear + Main Cam for gear tooth damage.
K-Mechanism: Approx Late 1990's-2002 - check loading motor pulley (splits), main gear (tooth damage) and slide plate (warped or split).
On the above usually F03,4 or 6 displayed on front panel, at failure.
G-Mechanism: Approx Early 1990's - check all gears for tooth damage + mech. relay.
NB: The gear teeth & mode switch on all the above must be realigned exactly. Information available in Panasonic service manuals.
Cobweb, November 2004