论文部分内容阅读
机型:上海牌Z237—1型彩电(转修机) 故障现象:“三无”,屡烧开关管。分析与检修:该机是TA四片机,开关电源与东芝X—56P机芯基本相同,由于屡损电源开关管,故先不通电,用电阻法检查。经检测,开关变压器T901的次级无短路现象,测电源开关管Q901,确已损坏。查振荡管Q902、Q903是好的,脉宽控制电容C910(47μF/25V)也无明显漏电。查过压保护电路Q905也是好的。若开
Model: Shanghai Z237-1-type color TV (switch repair machine) Symptom: “three no”, repeatedly burning switch. Analysis and Maintenance: This machine is TA four-chip machine, switching power supply and Toshiba X-56P movement is basically the same, due to the repeated loss of power switch, it is not the first electricity, with the resistance test. After testing, the secondary switch T901 transformer short-circuit phenomenon, measuring the power switch Q901, indeed damaged. Check the oscillation tube Q902, Q903 is good, pulse width control capacitor C910 (47μF / 25V) and no significant leakage. Check overvoltage protection circuit Q905 is also good. If the open