给一台环宇51C2电视机更换“汇佳”第五代主板,更换了主板以后,进行了各项指标的调试,(进入 I~2C 总线)基本上都没有什么问题了,图像和伴音都很正常,但是,当转换到 AV 状态的时候,播放 VCD 碟片,图像没有彩色,伴音正常。此时,屏幕上显示的是“视频”,在视频字符的下面显示“N4.43”的字符,这时候发现是制式不对,但是用 VCD 影碟机的遥控器,对着影碟机按遥控器上的“制式转换”键,不起作用。不管是转换到 PAL 制式上,还是转换到 NTSC 的制式上,场幅有变化,但是就是无彩色。后来,试探性的按压电视机遥控器上的各个按键,当按压到“系统”键时,在“视频”字符下面的字符发生变化,每按压一次该键,便依次出现 N3.58、N4.43、PAL、AUTO等字符,按到出现 AUTO(自动)和 PAL 时,图 To a Universal 51C2 TV replacement “Huijia” fifth-generation motherboard, motherboard replacement, the various indicators of debugging, (into the I ~ 2C bus) basically no problem, the image and sound are very Normal, however, when converted to AV when playing VCD discs, the picture is not color, sound normal. At this point, the screen shows the “video” in the video characters below the display “N4.43” characters, this time found to be wrong, but with the VCD player remote control, press the player on the remote control The “standard conversion” key, does not work. Whether it is converted to PAL format, or converted to NTSC standard, the field has changed, but is no color. Later, tentatively press each button on the TV remote control, when pressed to the “System” button, the characters under the “Video” character change. Each time the button is pressed, N3.58 and N4 appear in sequence. 43, PAL, AUTO and other characters, press until AUTO (Auto) and PAL, the figure