My fisher & paykel dishdrawer model DD603M top drawer not working?

Fisher & Paykel dishdrawers model DD603M
Hi -the top drawer stopped working quite awhile ago - at first it got stuck midcycle ( kept running but time & wash cycle didn't progress) but now does a 4 beep alarm when I try to start it - I've tried unplugging it, changing the wash program both multiple times but am really tired of just having 1 drawer! The alarm noise is the same as when the drawer isn't closed properly & you try to start it. I've held it firmly in place while trying to start it but still no luck. Any help wouldbe appreciated - thanks, Shari