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例1 IX0172CE的修复 IX0172CE是视频、色度、行扫描信号处理电路,主要应用在夏普C—1850CK型彩色电视机上,当电视机出现无规律的场跳动故障时,IX0172CE的⒄脚一般表现为低电平。⒄脚除有对比度、色度控制功能外,还兼有PAL—D/NTSC的制式转换功能,高电平(3.8 V)为50 Hz场频,适合于我国电视系统。⒄脚由R403、R404分压后NTSC获得高电平,使场频固定在50Hz上。如果⒄脚电压偏低,必然使场颇偏离50Hz,从而出现帧跳动。引起⒄脚电压偏低的主要原因是:R403、R404变质或IC内部故障。如果是IC内部故障引起⒄脚电压下降,而又无其他异常情况,可将R403、R404拆除,用两只3.3 kΩ可调电阻代换。两者配合调整,使⒄脚
Example IX0172CE repair IX0172CE is a video, chrominance, line scan signal processing circuit, mainly used in Sharp C-1850CK color TV set, when the TV appears irregular field beat failure, IX0172CE the tingling feet generally showed low Level. In addition to the contrast and chroma control functions, the pin function also has the PAL-D / NTSC standard conversion function. The high level (3.8 V) is 50 Hz and suitable for the television system in our country. Foot by the R403, R404 partial pressure NTSC get high, the field frequency fixed at 50Hz. If the foot voltage is low, the field is bound to deviate from 50Hz, resulting in frame beating. The main reason causing the foot voltage is low: R403, R404 deterioration or IC internal fault. If it is IC internal fault caused by foot drop voltage, but no other abnormalities, can be R403, R404 removed, with two 3.3 kΩ adjustable resistance substitution. With the adjustment of the two, so stomping feet