My MZ-7 died with following symptoms: - First it moved film with delay forward. - Then it stopped to work leaving display active (independent of power switch position). - Changing batteries caused display back light to be always on and nothing else happens.

Hi Jessica Yacopino - Generally speaking, Frigidaire air conditioners timer option typically have the same procedure. The unit must be in the ON position for the timer delay stop option. For delay start, the unit must be in the OFF position. First, press time button. Then to adjust timer setting, tap or hold the UP arrow or the DOWN arrow to change delay timer at .5 hour increments, up to 10 hours, then by 1 hour increments up to 24 hours. The control will count down the time remaining until start (8, 7.5, 7, etc.). The Delay Start mode automatically selects cooling with maximum Fan Speed. The temperature maintained will be the same as previously set. To change the set temperature, press "COOL" then Up or Down arrows until the desired temperature is indicated on the display. After 5 seconds, the control will automatically change the display back to the hours remaining until the unit will start/stop. PRESSING the unit On/Off button at any time will cancel the Delay Start/Stop function. The Delay Start/Stop Feature will work until the unit either starts or stops. Once that happens the above steps have to be repeated again.