Ford ranger tailgate

my 2001 ford ranger flairside pick-em-up truck has a faulty handle. i cannot lower the tailgate. after buying the truck used, i found the tailgate did not work. i had the mechanism replaced, it worked for about two days, then failed. the mechanic readjusted it, it worked for a few days, then died again. any thoughts?

Here is a link that show the tailgate mechanism. The handle is attached to two rods that are connected to latches on the side of the tailgate. Perhaps one of the rods detached.