Defective mechanism, a stucked mechanism is present. camcorder are smart it can detects error and shuts down itself for safety. earlier models dominoes the defect if the user is not quick enough to react when something goes wrong with the camera. You need professional service to fix it. Check your tapes carefully, most cause of this trouble are due to defective tapes, especially sony brand, I recommend you use TDK tapes.
never force open any unit, it will only make things worst!!! [;0)
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