DST1062B Symptom and Analysis
One day suddenly found that the oscilloscope waveform wrong, ripple greatly increased, and the measurements have more ripple, carefully test it, have a direct relationship with the human touch, human contact, the ripple will be more
Which should show a smooth sine wave, the result is superimposed on a large number of ripple ..
Then, I received a probe test signal port on the machine
Fortunately, in addition to larger ripple
But when I put fingers touched the machine test signal output port,
Same as the avalanche signal.
I think that the oscilloscope is broken, the door manufacturer sales, said ground not connected or not connected the probe ground, but I have ruled out two and I tried to use isolation transformers, no effect.
Intended to repair a few days, then normal the next day.
I believe the problem is not solved, not attack it is only temporary, and sure enough, today appeared the same problem, but there is no home digital television signals (add, digital television signals are often not on the door that my family and household, upstairs downstairs has a signal), I doubt there is ground, I measured a little electricity, the results have found that
Ground there is always the case with the zero line between the 26V AC, I remember that usually only a few tenths V voltage, which shows ground poorly grounded,
I do not know someone to steal power or bad, because most of the time is good and I will continue to monitor this phenomenon, because the family of digital television has been bad repair.