This machine insert with box you have audio playback, explain cassette tape is normal; Observed electronic video display head jam "X" characters and flashing, suspected of snowflakes noise point is the head caused by dirt. Pop-up box, wipe the video with a chamois leather bag head rod head in a box of a better quality of image after replay with box, failure remains the same. Using oscilloscope to observe the head signal amplification IC5001 (5) feet output rf signal envelope, found that not only the amplitude is small, and the waveform is incomplete, judge fault on a video head. After teardown with a magnifying glass observation, found a video head has been damaged, causing replay radio frequency envelope signal loss. Commissioning, after new image back to normal, troubleshooting.FWWservice manual download site