The lever on my DEXP toaster (model TSR-2000) stopped locking. I've encountered a similar repair before, on a Hotpoint-Ariston TT 22M DC0 toaster (incidentally, these two toasters are almost identical internally, but significantly more expensive), although it's hard to call it a repair; it's more of a cleaning. Ultimately, we disassembled the appliance and discovered a clogged coil that magnetizes the metal element of the lever and holds it in place. Bread crumbs were the culprit, leaving a residue that was easily removed with rubbing alcohol and a cotton swab.