眾所(suo)周知(zhi)(zhi)，日(ri)常生活中我們使(shi)用功(gong)放機(ji)，時間久(jiu)了之后可能(neng)就會出現各種(zhong)(zhong)各樣的問(wen)(wen)題(ti)，那(nei)么，功(gong)放機(ji)出現問(wen)(wen)題(ti)的情況下應該怎(zen)么解決(jue)呢(ni)？隔山如(ru)隔行，雖然(ran)不(bu)是(shi)所(suo)有的人(ren)都(dou)能(neng)解決(jue)的，但是(shi)了解一些相關方面(mian)的知(zhi)(zhi)識(shi)會使(shi)你(ni)迎刃而解。下面(mian)介紹功(gong)放機(ji)的三種(zhong)(zhong)常見故(gu)障及維修方法(fa)。

一、整機不工作(zuo)

整(zheng)機不工作的(de)故障表現為通(tong)電后放大器無(wu)任何顯示，各功(gong)能鍵均(jun)失效(xiao)，也(ye)無(wu)任何聲音，像未通(tong)電時一樣。

檢修時(shi)首(shou)先應檢查電(dian)(dian)(dian)源電(dian)(dian)(dian)路(lu)。可(ke)用萬用表(biao)測(ce)量電(dian)(dian)(dian)源插頭兩端的(de)(de)直流(liu)電(dian)(dian)(dian)阻值(zhi)(zhi)(zhi)(電(dian)(dian)(dian)源開(kai)關(guan)應接(jie)通(tong))，正常時(shi)應有(you)數百歐(ou)姆的(de)(de)電(dian)(dian)(dian)阻值(zhi)(zhi)(zhi)。若(ruo)測(ce)得阻值(zhi)(zhi)(zhi)偏小許多，且電(dian)(dian)(dian)源變壓器(qi)嚴(yan)重發熱，說明電(dian)(dian)(dian)源變壓器(qi)的(de)(de)初(chu)級(ji)(ji)回路(lu)有(you)局部短路(lu)處；若(ruo)測(ce)得阻值(zhi)(zhi)(zhi)為(wei)大(da)，應檢查保險絲是否熔(rong)斷、變壓器(qi)初(chu)級(ji)(ji)繞組是否開(kai)路(lu)、電(dian)(dian)(dian)源線與(yu)插頭之間有(you)無斷線。有(you)的(de)(de)機器(qi)增加(jia)了溫度保護裝(zhuang)置(zhi)，在電(dian)(dian)(dian)源變壓器(qi)的(de)(de)初(chu)級(ji)(ji)回路(lu)中接(jie)人了電(dian)(dian)(dian)流(liu)保險絲(通(tong)常安裝(zhuang)在電(dian)(dian)(dian)源變壓器(qi)內部，將變壓器(qi)外部的(de)(de)絕(jue)緣紙去(qu)掉即可(ke)見到)，它損壞后也會使電(dian)(dian)(dian)源變壓器(qi)初(chu)級(ji)(ji)回路(lu)開(kai)路(lu)。

四虎國產精品永久一區: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(er)、噪聲大

放(fang)大器的(de)噪(zao)聲(sheng)有交流聲(sheng)、爆裂(lie)聲(sheng)、感(gan)應噪(zao)聲(sheng)和白噪(zao)聲(sheng)等。

檢修(xiu)時，應先判斷噪(zao)聲(sheng)來自于前級(ji)還是來自于后級(ji)電(dian)(dian)路(lu)。可把前、后級(ji)的(de)信號(hao)連接插(cha)頭取下，若噪(zao)聲(sheng)明顯變(bian)小，說明故障在前級(ji)電(dian)(dian)路(lu)；反之(zhi)，故障在后級(ji)電(dian)(dian)路(lu)。交(jiao)流(liu)聲(sheng)是指聽(ting)感(gan)低(di)沉、單調而穩定的(de)100Hz交(jiao)流(liu)哼聲(sheng)，主要(yao)是電(dian)(dian)源(yuan)部分濾(lv)波(bo)不良(liang)所致(zhi)，應著(zhu)重檢查電(dian)(dian)源(yuan)整流(liu)、濾(lv)波(bo)和穩壓元(yuan)件有(you)無(wu)損壞。前、后級(ji)放大電(dian)(dian)路(lu)電(dian)(dian)源(yuan)端的(de)退(tui)耦電(dian)(dian)容虛焊或(huo)失(shi)效，也會產(chan)生一種類似交(jiao)流(liu)聲(sheng)的(de)低(di)頻振蕩噪(zao)聲(sheng)。

感應(ying)噪聲(sheng)(sheng)是(shi)(shi)成分(fen)較(jiao)復雜且刺耳的(de)(de)(de)(de)交流聲(sheng)(sheng)，主要是(shi)(shi)前級(ji)(ji)電(dian)(dian)(dian)路(lu)中(zhong)的(de)(de)(de)(de)轉換(huan)開關、電(dian)(dian)(dian)位(wei)器(qi)(qi)接地(di)不(bu)(bu)良(liang)或信(xin)(xin)號連線屏(ping)蔽不(bu)(bu)良(liang)所致。爆裂(lie)聲(sheng)(sheng)是(shi)(shi)指(zhi)間斷(duan)的(de)(de)(de)(de)“劈(pi)啪”、“咔(ka)咔(ka)”聲(sheng)(sheng)，在前級(ji)(ji)電(dian)(dian)(dian)路(lu)中(zhong)，應(ying)檢(jian)查信(xin)(xin)號輸(shu)(shu)入(ru)插頭與(yu)插座、轉換(huan)開關、電(dian)(dian)(dian)位(wei)器(qi)(qi)等是(shi)(shi)否(fou)接觸不(bu)(bu)良(liang)，耦合電(dian)(dian)(dian)容(rong)有無虛焊、漏電(dian)(dian)(dian)等。后級(ji)(ji)放(fang)大(da)電(dian)(dian)(dian)路(lu)應(ying)檢(jian)查繼電(dian)(dian)(dian)器(qi)(qi)觸點是(shi)(shi)否(fou)氧(yang)化、輸(shu)(shu) 入(ru)耦合電(dian)(dian)(dian)容(rong)有無漏電(dian)(dian)(dian)或接觸不(bu)(bu)良(liang)。另(ling)外，后級(ji)(ji)電(dian)(dian)(dian)路(lu)中(zhong)的(de)(de)(de)(de)差分(fen)輸(shu)(shu)入(ru)管或恒(heng)流管軟擊穿，也會(hui)產生類似(si)電(dian)(dian)(dian)火花的(de)(de)(de)(de)“咔(ka)咔(ka)”噪聲(sheng)(sheng)。白噪聲(sheng)(sheng)是(shi)(shi)指(zhi)無規則的(de)(de)(de)(de)連續“沙沙”聲(sheng)(sheng)，通常是(shi)(shi)由前、后級(ji)(ji)放(fang)大(da)電(dian)(dian)(dian)路(lu)中(zhong)的(de)(de)(de)(de)輸(shu)(shu)入(ru)級(ji)(ji)晶(jing)體(ti)管、場效應(ying)管或運放(fang)集成電(dian)(dian)(dian)路(lu)的(de)(de)(de)(de)性(xing)能不(bu)(bu)良(liang)產生的(de)(de)(de)(de)本底(di)噪聲(sheng)(sheng)，檢(jian)修(xiu)時，可用同規格的(de)(de)(de)(de)元件代換(huan)試之。

三、音量輕

專業四虎國產精品永久一區: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(yi)上各部分均(jun)正常，應判斷出(chu)故障是在(zai)前(qian)級還(huan)是在(zai)后級電(dian)(dian)路。對于某一個聲(sheng)道音(yin)(yin)輕，可將其前(qian)級電(dian)(dian)路輸(shu)出(chu)的(de)(de)(de)信號交換輸(shu)入到另一聲(sheng)道的(de)(de)(de)后級電(dian)(dian)路，若音(yin)(yin)箱的(de)(de)(de)聲(sheng)音(yin)(yin)大小不變(bian)，則故障在(zai)后級電(dian)(dian)路；反之(zhi)，故障在(zai)前(qian)級電(dian)(dian)路。后級放大電(dian)(dian)路造成的(de)(de)(de)音(yin)(yin)輕，主要有輸(shu)出(chu)功率不足和(he)增益(yi)不夠兩(liang)種(zhong)原因。可用適當加(jia)大輸(shu)入信號(例如將收錄(lu)機輸(shu)出(chu)給揚聲(sheng)器的(de)(de)(de)信號直接(jie)加(jia)至(zhi)后級功放電(dian)(dian)路的(de)(de)(de)輸(shu)入端，改變(bian)收錄(lu)機的(de)(de)(de)音(yin)(yin)量，觀察功放輸(shu)出(chu)的(de)(de)(de)變(bian)化)的(de)(de)(de)方法來判斷是哪種(zhong)原因引起的(de)(de)(de)。

若加(jia)大(da)輸(shu)入信號(hao)(hao)后(hou)(hou)，輸(shu)出(chu)的(de)(de)聲(sheng)音(yin)足(zu)夠大(da)，說(shuo)明功(gong)放輸(shu)出(chu)功(gong)率(lv)足(zu)夠，只是增(zeng)益降低(di)(di)，應(ying)著重檢(jian)查(cha)繼電(dian)(dian)(dian)(dian)(dian)器(qi)觸點有無(wu)接觸電(dian)(dian)(dian)(dian)(dian)阻(zu)增(zeng)大(da)、輸(shu)入耦合電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)減(jian)小(xiao)、隔(ge)離電(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值(zhi)增(zeng)大(da)、負反(fan)饋電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)變小(xiao)或(huo)(huo)開路(lu)、負反(fan)饋電(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值(zhi)增(zeng)大(da)或(huo)(huo)開路(lu)等現象。若加(jia)大(da)輸(shu)入信號(hao)(hao)后(hou)(hou)，輸(shu)出(chu)的(de)(de)聲(sheng)音(yin)出(chu)現失真，音(yin)量(liang)并無(wu)顯著增(zeng)大(da)，說(shuo)明后(hou)(hou)級放大(da)器(qi)的(de)(de)輸(shu)出(chu)功(gong)率(lv)不(bu)足(zu)，應(ying)先檢(jian)查(cha)放大(da)器(qi)的(de)(de)正、負供(gong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓是否(fou)偏低(di)(di)(若只是一個聲(sheng)道音(yin)輕，可不(bu)必(bi)檢(jian)查(cha)電(dian)(dian)(dian)(dian)(dian)源(yuan)供(gong)電(dian)(dian)(dian)(dian)(dian))、功(gong)率(lv)管或(huo)(huo)集(ji)成電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)性能是否(fou)變差(cha)、發射極電(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值(zhi)有無(wu)變大(da)等。前(qian)級電(dian)(dian)(dian)(dian)(dian)路(lu)中轉換開關、電(dian)(dian)(dian)(dian)(dian)位器(qi)所造(zao)(zao)成的(de)(de)音(yin)輕，采用(yong)直(zhi)觀(guan)檢(jian)查(cha)較易發現，可對其進(jin)行清洗(xi)或(huo)(huo)更換。如懷疑某信號(hao)(hao)耦合電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)失效(xiao)，可用(yong)同值(zhi)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)并聯(lian)試之；放大(da)管或(huo)(huo)運放集(ji)成電(dian)(dian)(dian)(dian)(dian)路(lu)性能不(bu)良，也可用(yong)代換法(fa)檢(jian)查(cha)。另外，負反(fan)饋元件有問題(ti)，也會(hui)造(zao)(zao)成電(dian)(dian)(dian)(dian)(dian)路(lu)增(zeng)益下降。