论文部分内容阅读
故障现象:伴音正常,图像顶部有3cm左右的回扫区,无屏显,且无论按动任一功能键都要出现5～6秒钟的黑屏。据用户讲,此机以前检修过,更换了色度、视频、扫描信号处理块、TA8759,但是没有解决问题。分析检修:根据故障现象和上次检修中所更换集成块,此故障应该在微处理CPU或者是场同步信号受阻,只要判断CPU的字符显示电路工作是否正常即可。检测CPU(CTV222S)(26)脚(行同步信号)电压为
Symptoms: normal sound, the top of the image around the back area of about 3cm, no screen, and no matter press any function key to appear 5 to 6 seconds of black screen. According to the user speaking, this machine overhaul before, replaced the chroma, video, scan signal processing block, TA8759, but did not solve the problem. Analysis and maintenance: According to the fault phenomenon and the replacement of the manifold in the last maintenance, this fault should be blocked in the microprocessor CPU or field synchronization signal, as long as the CPU to determine the character display circuit is working properly. Check CPU (CTV222S) (26) pin (line sync signal) voltage is