assuming the batteries used to replace old where new, i'd check if they're installed correctly, if so is the remote original to system because some after market remotes need to be reprogramed after batteries are removed. If this is not the case, next check to see if there are no obstructions blocking the units remote control sensor usually a smoked black or red square of plastic or near a red led light, gently clean with a damp not wet cotton cloth, if this still doesn't work, I've disassembled the remote control and clean press button contacts under buttons with a Q tip dab in alcohol to remove any dust or debris that may acumilate over time, let alcohol air dry and do reverse of disassembly. Hope any of this helps you out good luck.
Joe
December 2007
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