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目前在16位和32位的IBM PC兼容机中常用8900C、9000(9000A或9000B)两种TVGA显示卡,其中8900C TVGA卡功能较强,电路也稍为复杂,根据笔者的维修经验,以89000 TVGA卡(下文简称卡)为例,对其常见故障的维修作一小结。1.无显示此时应该注意两种情况(可根据自检时扬声器的发声或专用诊断测试卡莱判断。对信号波形较为熟悉者,用示波器测量I/O槽上的信号亦能判断)。第一种情况是主机板在插上卡后,开机BIOS不能进入自检,立即死机。此时显然是与丰机板接口的卡的总线(指系统总线,以下同)部分出了致命的故障,导致主机板不能启动。常见的故障是卡上的低8位数据线之间或低位地址线之间存在短路,或对地、对+5V有短路。测试方法可把卡插在主机板上,用万用表静态测量I/O槽上低8位
Currently in the 16-bit and 32-bit IBM PC compatible 8900C, 9000 (9000A or 9000B) commonly used two TVGA graphics card, which 8900C TVGA card features a more complex circuit, according to the author’s maintenance experience to 89000 TVGA Card (hereinafter referred to as the card), for example, a summary of the maintenance of its common failures. 1. No display At this point, you should pay attention to two situations (according to the speaker’s audible self-test or a dedicated diagnostic test Callaway judgment.) Signal waveform more familiar with the oscilloscope to measure the signal on the I / O slot can judge). The first case is the motherboard plug in the card, the boot BIOS can not enter the self-test, immediately crashes. At this point, it is obviously a fatal fault on the bus (referring to the system bus, the same below) of the card that interfaces with the FPC board, so that the board can not be started. A common fault is the short circuit between the lower 8 data lines on the card or between the lower address lines, or a short to + 5V. Test method can be inserted in the motherboard card, with a multimeter static measurement I / O slot on the low 8