DST1062B故障现象与分析有一天突然发现示波器波形不对了纹波大增而.DOC

DST1062B故障现象与分析 有一天突然发现,示波器波形不对了,纹波大增,而且测量时有更多的纹波,仔细测试了一下,与人体触摸有直接关系,人体接触之后 ,纹波会更多 DST1062B?Symptom?and AnalysisOne day?suddenly?found that?the oscilloscope?waveform?wrong,?ripple?greatly increased, and the?measurements?have more?ripple,?carefully?test it,?have a directrelationship?with the?human?touch,?human contact, the?ripple?will be more 本来应该显示光滑的正弦波的,结果却叠加了大量的纹波.. hich should?show?a smooth?sine wave, the result is?superimposed on?a lot ofripple. 然后,我把探头接到了本机测试信号口上 Then,?I?received a?probe?test signal?port?on?the machine 除了纹波大一点还好 Fortunately,?in addition to?larger?ripple 但是,当我把手指碰到本机测试信号输出端口时, But when?I put?fingers touched?the machine?test?signal output?port, 信号像雪崩一样了. Same?as the?avalanche?signal. 我以为示波器坏了,问厂家售后,说是地线没接好,或探头地线没接好,但这两点我都排除了.我也用隔离变压器试过,没有效果. I?think that?the oscilloscope?is broken,?ask?the manufacturers?sales,?said?groundnot?connected?or?not?connected?the probe?ground, but?I have?ruled out?two?and Itried?to use?isolation?transformers,?no effect. 本打算过几天去维修,结果第二天又正常了. ntended?to repair?a few days,?then?normal?the next day. 我相信问题并没有解决,只是暂时没发作而已,果然,今天又出现了同样的问题,而且家里的数字电视也没有信号(补充一下,数字电视经常没信号,就我家与对门那户,楼上楼下都有信号),我怀疑地线有问题,我测量了一下市电,结果又有发现, 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?digitaltelevision?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, Imeasured?a little?electricity, the results?have?found that 地线与零线之间尽然有26V交流电,我记得平时只有零点几V电压的,这说明地线接地不良, 不知道是有人在偷电还是接触不良,因为大多数时候是好的.我会继续跟踪这个现象,因为家里的数字电视一直修不好. 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 goodand I?will continue to?monitor this?phenomenon,?because the family?of?digitaltelevision?has been?bad repair.