Analysis and overhaul, "failed" appears, log M69032P {23} feet low, {24}, {25} feet rotated as 00, 01, 10, 11, shows the sequence test control circuit, the "fault" should be in the TEST circuit. Suspected TEST switch is bad, replacement of the tact switch, the "fault" as ever. Suspected adverse TC4013, replaced, still the same. Fine check TC4013 perimeter circuit, found principle figure in the TEST switch next of anti-interference capacitor for 4.7 μ f, and actual using of is 0.027 μ f, whether manufacturers plug wrong components? try for 4.7 μ f, found TEST press reaction slow (Dang by Xia, and relax Zhijian of time too short Shi, operation invalid), but "fault" appeared of probability reduced many, but still exists, description components is manufacturers for of late changes. In the schematic analysis to analyze, no abnormalities were found, maintenance, ran into trouble, but suspect the exhaust line is bad, check and found myself suddenly clear: TEST control level from STPB-11 to STPA-11 and STPB-8 to STPA-8 only to a Dolby decoder Board and aim at the foot of the TC4013, Middle after two sets of lines and winding copper wire. Transmission distance, and involved a lot of opportunities, and anti-interference capacitors and third leg CLK end away from the TC4013, resulting in lines induced interference noise very easily rushed into the control end of the trigger, causing false triggering, automatically enter the sequence of noise test. TC4013 ③ feet nearest the retrofitting of a 0.027 μg f capacitor, boot for longer playback tests were normal, "failed" excluded.Ga8service manual download site