<p><img src="attachments/dvbbs/2006-8/20068290202560966.bmp" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor=\'hand\'; this.alt=\'Click here to open new window\nCTRL+Mouse wheel to zoom in/out\';}" onclick="if(!this.resized) {return true;} else {window.open(\'attachments/dvbbs/2006-8/20068290202560966.bmp\');}" onmousewheel="return imgzoom(this);" alt="" /></p><p>(看图中箭头)PSON从75脚进入I/O,经I/O转换后从72脚输出到南桥,再经南桥处理后由71脚输回I/O,I/O处理后拉低76脚电压(也就是ATX绿线)开机!</p><p>PS:修的板子很少!只能给些测量的经验,72和71脚都应该是高电位(3.3V),按下PSON开关后会被拉低!测72脚没高电压的话我见过一两块是3VSB的供电电阻R6坏(有些板可能是一排阻),也有可能是南桥有短路引起没电压,可以分别断开71脚72脚连接到南桥的线来测量一下!别外67脚SB电压我测量好多板都是3.3V而不是5V</p><p>以上只是个人看法,如有不同意见欢迎发表[em05][em05]</p>
[此贴子已经被作者于2006-8-29 0:54:53编辑过]
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