On most Panasonic, error code HO3 indicates a mechanical problem, more specifically, the cradle that supports the laser eye could not traverse along its path. Corrective action requires opening the unit, cleaning the slider bar, plastic cogs, worm gear/drive. It may help to use a can of compressed air and re-lubricate appropriate parts. Since the unit is open and expectantly dust would be swirling after the use of the compressed air, it may be to your advantage to swab/clean the lens itself prior to closing.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
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