Horn Strobe Replacement Needed The freezer's fire alarm horn strobe is currently obstructed by ice accumulation, worsened by a malfunctioning end-of-line resistor that has broken. To rectify the situation and ensure reliable fire alarm functionality, the device needs to be replaced. Alarm Systems Repair Need to order new Outdoor ceiling horn strobe. Need to return to replace device and E.O.L resistor. Deficiency: Freezer AV full of ice. Broke EOL resistor. Need to replace device.