眾所周知，日常生活中我們使(shi)用功(gong)放(fang)機，時間久(jiu)了之(zhi)后可能就會出(chu)現各種各樣的(de)問(wen)題，那么(me)，功(gong)放(fang)機出(chu)現問(wen)題的(de)情況下應該怎么(me)解決(jue)呢？隔(ge)山(shan)如隔(ge)行，雖然不(bu)是所有的(de)人都(dou)能解決(jue)的(de)，但是了解一些相關方面(mian)的(de)知識會使(shi)你迎(ying)刃而解。下面(mian)介紹功(gong)放(fang)機的(de)三(san)種常見故障及維修方法。

一、整機不工作

整機(ji)不工(gong)作的(de)故障表現(xian)為(wei)通電(dian)后放(fang)大器無(wu)(wu)任何顯示(shi)，各功能鍵均失效(xiao)，也無(wu)(wu)任何聲音(yin)，像(xiang)未(wei)通電(dian)時一樣(yang)。

檢修(xiu)時(shi)首(shou)先應檢查(cha)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)電(dian)(dian)(dian)路(lu)。可用萬用表測量電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)插(cha)頭(tou)兩端的(de)(de)直流(liu)電(dian)(dian)(dian)阻值(zhi)(zhi)(電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)開(kai)(kai)關(guan)應接(jie)(jie)通(tong))，正(zheng)常時(shi)應有(you)數百歐姆的(de)(de)電(dian)(dian)(dian)阻值(zhi)(zhi)。若測得阻值(zhi)(zhi)偏(pian)小許多，且(qie)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)變壓(ya)器(qi)(qi)(qi)(qi)嚴重發(fa)熱，說明電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)變壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)初(chu)級(ji)回(hui)(hui)路(lu)有(you)局部短路(lu)處；若測得阻值(zhi)(zhi)為大，應檢查(cha)保險絲是(shi)否(fou)熔斷、變壓(ya)器(qi)(qi)(qi)(qi)初(chu)級(ji)繞組是(shi)否(fou)開(kai)(kai)路(lu)、電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)線(xian)與插(cha)頭(tou)之間有(you)無斷線(xian)。有(you)的(de)(de)機器(qi)(qi)(qi)(qi)增加了(le)溫(wen)度(du)保護(hu)裝(zhuang)置，在(zai)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)變壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)初(chu)級(ji)回(hui)(hui)路(lu)中接(jie)(jie)人了(le)電(dian)(dian)(dian)流(liu)保險絲(通(tong)常安裝(zhuang)在(zai)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)變壓(ya)器(qi)(qi)(qi)(qi)內(nei)部，將變壓(ya)器(qi)(qi)(qi)(qi)外部的(de)(de)絕緣紙去掉即可見到)，它損壞后也(ye)會使(shi)電(dian)(dian)(dian)源(yuan)(yuan)(yuan)(yuan)變壓(ya)器(qi)(qi)(qi)(qi)初(chu)級(ji)回(hui)(hui)路(lu)開(kai)(kai)路(lu)。

香蕉app下載汅api免費秋葵網站在線觀看:重慶音響工程公司稱若電源插頭兩端阻值正常，可通電測量電源電路各輸出電壓是否正常。對于采用系統控制微處理器或邏輯控制電路的放大器，應著重檢查該控制電路的供電電壓(通常為+5V)是否正常。如無+5V電壓，應測量三端穩壓集成電路7805的輸入端電壓是否正常，若輸入端電壓不正常，應檢查整流、濾波電路。若7805輸入端電壓正常，而輸出端無十5V電壓或電壓偏低，可斷開負載看+5V電壓能否恢復正常。若+5V電壓正常，則故障在負載電路；若+5V電壓仍不正常，則故障在7805本身。若系統控制電路的+5V供電電壓正常，應再檢查微處理器的時鐘及復位信號是否正常、鍵控與顯示驅動電路有無損壞。

二、噪聲大

放大器的噪(zao)聲(sheng)有交流(liu)聲(sheng)、爆裂聲(sheng)、感應(ying)噪(zao)聲(sheng)和白(bai)噪(zao)聲(sheng)等。

檢修時(shi)，應(ying)先判斷噪(zao)聲(sheng)(sheng)來自于前級(ji)還是來自于后級(ji)電(dian)路。可(ke)把前、后級(ji)的信號連接插頭取下(xia)，若噪(zao)聲(sheng)(sheng)明顯變小，說明故障在(zai)前級(ji)電(dian)路；反之，故障在(zai)后級(ji)電(dian)路。交流(liu)聲(sheng)(sheng)是指聽感低沉、單(dan)調而穩定的100Hz交流(liu)哼聲(sheng)(sheng)，主要是電(dian)源部分濾(lv)波(bo)不(bu)良所致，應(ying)著重檢查電(dian)源整流(liu)、濾(lv)波(bo)和穩壓元件有無損壞。前、后級(ji)放大電(dian)路電(dian)源端的退耦(ou)電(dian)容虛焊或失效，也會產生(sheng)一種類(lei)似交流(liu)聲(sheng)(sheng)的低頻振(zhen)蕩噪(zao)聲(sheng)(sheng)。

感應噪(zao)聲是(shi)(shi)(shi)成分較復(fu)雜(za)且刺耳(er)的(de)交流聲，主要(yao)是(shi)(shi)(shi)前級(ji)(ji)電(dian)(dian)(dian)路中的(de)轉換(huan)開關、電(dian)(dian)(dian)位(wei)器接地(di)不良(liang)或(huo)(huo)信號連(lian)線(xian)屏蔽(bi)不良(liang)所致。爆裂聲是(shi)(shi)(shi)指間斷的(de)“劈啪”、“咔(ka)(ka)(ka)咔(ka)(ka)(ka)”聲，在前級(ji)(ji)電(dian)(dian)(dian)路中，應檢查信號輸(shu)(shu)(shu)入插頭與插座、轉換(huan)開關、電(dian)(dian)(dian)位(wei)器等是(shi)(shi)(shi)否接觸不良(liang)，耦(ou)合(he)電(dian)(dian)(dian)容(rong)有無虛焊、漏(lou)(lou)電(dian)(dian)(dian)等。后級(ji)(ji)放大(da)電(dian)(dian)(dian)路應檢查繼電(dian)(dian)(dian)器觸點是(shi)(shi)(shi)否氧(yang)化、輸(shu)(shu)(shu) 入耦(ou)合(he)電(dian)(dian)(dian)容(rong)有無漏(lou)(lou)電(dian)(dian)(dian)或(huo)(huo)接觸不良(liang)。另外，后級(ji)(ji)電(dian)(dian)(dian)路中的(de)差分輸(shu)(shu)(shu)入管或(huo)(huo)恒(heng)流管軟擊穿，也會產生(sheng)類(lei)似電(dian)(dian)(dian)火花的(de)“咔(ka)(ka)(ka)咔(ka)(ka)(ka)”噪(zao)聲。白(bai)噪(zao)聲是(shi)(shi)(shi)指無規則的(de)連(lian)續(xu)“沙(sha)沙(sha)”聲，通(tong)常是(shi)(shi)(shi)由前、后級(ji)(ji)放大(da)電(dian)(dian)(dian)路中的(de)輸(shu)(shu)(shu)入級(ji)(ji)晶(jing)體管、場效應管或(huo)(huo)運放集成電(dian)(dian)(dian)路的(de)性能不良(liang)產生(sheng)的(de)本底噪(zao)聲，檢修(xiu)時，可用同規格的(de)元件代換(huan)試之(zhi)。

三、音(yin)量(liang)輕

專業香蕉app下載汅api免費秋葵網站在線觀看:音響工程公司稱所謂音輕故障，是指音頻信號在放大傳輸過程中，因某個放大級放大量變化或在某個環節被衰減，使放大器的增益下降或輸出功率變小。檢修時，首先應檢查信號源和音箱是否正常，可用替換的辦法來檢查。然后檢查各類轉換開關和控制電位器，看音量能否變大。

若以上各部分均正常，應判斷出(chu)故障(zhang)是在前(qian)級(ji)(ji)還是在后(hou)級(ji)(ji)電路(lu)。對于某一個(ge)聲道(dao)音(yin)(yin)輕(qing)，可(ke)將(jiang)其前(qian)級(ji)(ji)電路(lu)輸(shu)出(chu)的(de)信號(hao)交換輸(shu)入到另(ling)一聲道(dao)的(de)后(hou)級(ji)(ji)電路(lu)，若音(yin)(yin)箱(xiang)的(de)聲音(yin)(yin)大(da)小(xiao)不(bu)變(bian)，則故障(zhang)在后(hou)級(ji)(ji)電路(lu)；反之，故障(zhang)在前(qian)級(ji)(ji)電路(lu)。后(hou)級(ji)(ji)放(fang)大(da)電路(lu)造(zao)成(cheng)的(de)音(yin)(yin)輕(qing)，主(zhu)要有(you)輸(shu)出(chu)功率(lv)不(bu)足和增益(yi)不(bu)夠兩種(zhong)(zhong)原(yuan)因。可(ke)用適當加大(da)輸(shu)入信號(hao)(例如將(jiang)收(shou)(shou)錄機(ji)輸(shu)出(chu)給揚聲器的(de)信號(hao)直(zhi)接加至(zhi)后(hou)級(ji)(ji)功放(fang)電路(lu)的(de)輸(shu)入端，改(gai)變(bian)收(shou)(shou)錄機(ji)的(de)音(yin)(yin)量，觀察功放(fang)輸(shu)出(chu)的(de)變(bian)化)的(de)方法(fa)來判斷是哪種(zhong)(zhong)原(yuan)因引起的(de)。

若加大(da)(da)輸(shu)入(ru)信號(hao)(hao)后(hou)，輸(shu)出(chu)的(de)聲(sheng)音(yin)足夠(gou)大(da)(da)，說明(ming)功(gong)放(fang)(fang)輸(shu)出(chu)功(gong)率足夠(gou)，只(zhi)是(shi)增(zeng)(zeng)益(yi)降(jiang)低，應著重(zhong)檢(jian)查(cha)繼電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)觸點有(you)無(wu)接觸電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)增(zeng)(zeng)大(da)(da)、輸(shu)入(ru)耦合電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)減小、隔離電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)增(zeng)(zeng)大(da)(da)、負(fu)反饋(kui)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)變(bian)小或(huo)(huo)開(kai)路(lu)、負(fu)反饋(kui)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)增(zeng)(zeng)大(da)(da)或(huo)(huo)開(kai)路(lu)等(deng)現(xian)象。若加大(da)(da)輸(shu)入(ru)信號(hao)(hao)后(hou)，輸(shu)出(chu)的(de)聲(sheng)音(yin)出(chu)現(xian)失真，音(yin)量(liang)并無(wu)顯著增(zeng)(zeng)大(da)(da)，說明(ming)后(hou)級放(fang)(fang)大(da)(da)器(qi)(qi)(qi)的(de)輸(shu)出(chu)功(gong)率不(bu)(bu)(bu)足，應先檢(jian)查(cha)放(fang)(fang)大(da)(da)器(qi)(qi)(qi)的(de)正、負(fu)供(gong)(gong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)否(fou)偏低(若只(zhi)是(shi)一個聲(sheng)道音(yin)輕(qing)，可不(bu)(bu)(bu)必檢(jian)查(cha)電(dian)(dian)(dian)(dian)(dian)源供(gong)(gong)電(dian)(dian)(dian)(dian)(dian))、功(gong)率管(guan)(guan)或(huo)(huo)集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)性(xing)能是(shi)否(fou)變(bian)差、發射(she)極電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)有(you)無(wu)變(bian)大(da)(da)等(deng)。前級電(dian)(dian)(dian)(dian)(dian)路(lu)中轉換(huan)(huan)開(kai)關、電(dian)(dian)(dian)(dian)(dian)位(wei)器(qi)(qi)(qi)所造(zao)(zao)成(cheng)的(de)音(yin)輕(qing)，采(cai)用(yong)(yong)直觀檢(jian)查(cha)較易發現(xian)，可對其進行(xing)清(qing)洗(xi)或(huo)(huo)更換(huan)(huan)。如懷(huai)疑某信號(hao)(hao)耦合電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)失效，可用(yong)(yong)同值(zhi)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)并聯(lian)試之；放(fang)(fang)大(da)(da)管(guan)(guan)或(huo)(huo)運(yun)放(fang)(fang)集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)性(xing)能不(bu)(bu)(bu)良(liang)，也可用(yong)(yong)代(dai)換(huan)(huan)法檢(jian)查(cha)。另外，負(fu)反饋(kui)元件(jian)有(you)問題，也會造(zao)(zao)成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)增(zeng)(zeng)益(yi)下(xia)降(jiang)。