西(xi)(xi)門子NCU維(wei)修(xiu)必須(xu)(xu)在對西(xi)(xi)門子840D系統維(wei)護前(qian)，必須(xu)(xu)對NC以(yi)及(ji)PLC程序做好備份。在通電(dian)情(qing)況下(xia)，取(qu)出(chu)西(xi)(xi)門子NCU-BOX正面電(dian)池(chi)與風(feng)(feng)扇插(cha)卡，可用工業(ye)酒(jiu)(jiu)精清(qing)(qing)洗(xi)，然后(hou)用電(dian)吹(chui)風(feng)(feng)烘干。西(xi)(xi)門子NCU維(wei)修(xiu)下(xia)面雙(shuang)風(feng)(feng)扇，可以(yi)直(zhi)接(jie)取(qu)下(xia)，用酒(jiu)(jiu)精清(qing)(qing)洗(xi)，電(dian)吹(chui)風(feng)(feng)烘干。在斷電(dian)情(qing)況下(xia)，將西(xi)(xi)門子NCU維(wei)修(xiu)一(yi)起取(qu)下(xia)，NCU主板(ban)小(xiao)心取(qu)出(chu)，打開(kai)BOX蓋子，取(qu)出(chu)電(dian)源板(ban)，用酒(jiu)(jiu)精清(qing)(qing)洗(xi)，電(dian)吹(chui)風(feng)(feng)烘干。

西(xi)(xi)門子(zi)NCU維修的方法(fa)：1.電源接通(tong)后無基本畫面顯示，電路板(ban)(ban)(ban)03840號板(ban)(ban)(ban)上(shang)無監(jian)(jian)控(kong)燈(deng)顯示，電路板(ban)(ban)(ban)上(shang)監(jian)(jian)控(kong)燈(deng)亮，監(jian)(jian)控(kong)燈(deng)閃爍，如果(guo)監(jian)(jian)控(kong)燈(deng)閃爍頻(pin)率(lv)為(wei)1Hz，則(ze)EPROM有(you)故(gu)障；如果(guo)閃爍頻(pin)率(lv)為(wei)2Hz，則(ze)PLC有(you)故(gu)障；如以(yi)4Hz頻(pin)率(lv)閃爍，則(ze)保持電池報警，表示電壓已(yi)不足。監(jian)(jian)控(kong)燈(deng)左滅右亮。西(xi)(xi)門子(zi)NCU維修表示操作面板(ban)(ban)(ban)的接口板(ban)(ban)(ban)03731板(ban)(ban)(ban)有(you)故(gu)障或CRT有(you)故(gu)障。通(tong)常的原(yuan)因有(you)：CPU有(you)故(gu)障；EPROM有(you)故(gu)障；系(xi)統總線（即(ji)背板(ban)(ban)(ban)）有(you)故(gu)障、電路板(ban)(ban)(ban)上(shang)設定(ding)有(you)誤、機床數據錯誤、以(yi)及電路板(ban)(ban)(ban)（如存儲(chu)器板(ban)(ban)(ban)、耦合板(ban)(ban)(ban)、測(ce)量板(ban)(ban)(ban)）的硬件(jian)有(you)故(gu)障。

西門子(zi)NCU維(wei)修由于電源板(ban)或存(cun)儲曾被拔出，從(cong)而(er)造成存(cun)儲區混(hun)亂(luan)。這是一種軟故障，只要(yao)將(jiang)CNC內部程序(xu)清除(chu)并重新輸入(ru)即(ji)可排除(chu)故障，電源板(ban)或存(cun)儲器板(ban)上的(de)硬件故障造成程序(xu)顯示混(hun)亂(luan)。在自動(dong)方(fang)式下程序(xu)不能(neng)啟動(dong)，如此時產生351號(hao)報警(jing)，表示西門子(zi)NCU維(wei)修啟動(dong)之后，未進行機床回基(ji)準點(dian)的(de)操作，系統處于自動(dong)保持狀態。