眾所周知，日常生活中我(wo)們使用功(gong)放(fang)(fang)(fang)機，時間(jian)久了之后(hou)可(ke)能(neng)就會出(chu)現(xian)各種(zhong)各樣的(de)(de)問(wen)題，那么，功(gong)放(fang)(fang)(fang)機出(chu)現(xian)問(wen)題的(de)(de)情(qing)況下(xia)應(ying)該怎么解(jie)決呢？隔(ge)山(shan)如隔(ge)行(xing)，雖(sui)然不(bu)是所有的(de)(de)人都能(neng)解(jie)決的(de)(de)，但是了解(jie)一些相關(guan)方面(mian)的(de)(de)知識會使你(ni)迎(ying)刃而(er)解(jie)。下(xia)面(mian)介紹(shao)功(gong)放(fang)(fang)(fang)機的(de)(de)三種(zhong)常見故障及維修方法。

一、整機不工作(zuo)

整機不工作的(de)故障表現為通電(dian)后(hou)放大器無(wu)任(ren)何顯示(shi)，各功能鍵均(jun)失效(xiao)，也(ye)無(wu)任(ren)何聲音，像未通電(dian)時一(yi)樣。

檢修時首先應(ying)(ying)檢查電(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)路。可用(yong)萬用(yong)表測(ce)量電(dian)(dian)(dian)源(yuan)插頭(tou)(tou)兩端的(de)(de)直流電(dian)(dian)(dian)阻值(zhi)(電(dian)(dian)(dian)源(yuan)開關應(ying)(ying)接(jie)通)，正常(chang)(chang)時應(ying)(ying)有(you)數百歐姆的(de)(de)電(dian)(dian)(dian)阻值(zhi)。若(ruo)測(ce)得(de)阻值(zhi)偏小許(xu)多，且電(dian)(dian)(dian)源(yuan)變壓(ya)器(qi)嚴重發熱，說明電(dian)(dian)(dian)源(yuan)變壓(ya)器(qi)的(de)(de)初級(ji)回路有(you)局部(bu)(bu)短路處；若(ruo)測(ce)得(de)阻值(zhi)為大，應(ying)(ying)檢查保險絲是否熔斷、變壓(ya)器(qi)初級(ji)繞(rao)組是否開路、電(dian)(dian)(dian)源(yuan)線與插頭(tou)(tou)之間有(you)無斷線。有(you)的(de)(de)機(ji)器(qi)增(zeng)加(jia)了溫度保護裝置，在(zai)電(dian)(dian)(dian)源(yuan)變壓(ya)器(qi)的(de)(de)初級(ji)回路中接(jie)人了電(dian)(dian)(dian)流保險絲(通常(chang)(chang)安裝在(zai)電(dian)(dian)(dian)源(yuan)變壓(ya)器(qi)內部(bu)(bu)，將(jiang)變壓(ya)器(qi)外部(bu)(bu)的(de)(de)絕緣紙去掉即可見到)，它損壞后(hou)也(ye)會(hui)使電(dian)(dian)(dian)源(yuan)變壓(ya)器(qi)初級(ji)回路開路。

中文字幕日韓歐美一區二區三區: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

放大器的(de)噪聲有交流(liu)聲、爆(bao)裂聲、感(gan)應噪聲和白噪聲等。

檢修時，應先判斷噪(zao)(zao)聲(sheng)來自(zi)于前(qian)級(ji)(ji)(ji)還是(shi)來自(zi)于后級(ji)(ji)(ji)電(dian)(dian)(dian)路。可把前(qian)、后級(ji)(ji)(ji)的(de)信(xin)號連接插頭取下，若噪(zao)(zao)聲(sheng)明顯變(bian)小，說明故(gu)障在前(qian)級(ji)(ji)(ji)電(dian)(dian)(dian)路；反之，故(gu)障在后級(ji)(ji)(ji)電(dian)(dian)(dian)路。交流聲(sheng)是(shi)指聽感低沉(chen)、單調而(er)穩(wen)定的(de)100Hz交流哼(heng)聲(sheng)，主要(yao)是(shi)電(dian)(dian)(dian)源部分(fen)濾波(bo)不良所致(zhi)，應著重檢查(cha)電(dian)(dian)(dian)源整流、濾波(bo)和穩(wen)壓元件(jian)有無損壞。前(qian)、后級(ji)(ji)(ji)放大電(dian)(dian)(dian)路電(dian)(dian)(dian)源端(duan)的(de)退耦電(dian)(dian)(dian)容虛(xu)焊(han)或失效，也會(hui)產生一種類似交流聲(sheng)的(de)低頻振蕩噪(zao)(zao)聲(sheng)。

感(gan)應噪聲(sheng)是(shi)成分(fen)較復(fu)雜且刺耳的(de)(de)交(jiao)流聲(sheng)，主要是(shi)前(qian)級(ji)(ji)電(dian)(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)轉(zhuan)(zhuan)換開(kai)(kai)關、電(dian)(dian)(dian)位器接地不(bu)良或信號連(lian)線屏蔽不(bu)良所致(zhi)。爆裂聲(sheng)是(shi)指間斷的(de)(de)“劈(pi)啪”、“咔咔”聲(sheng)，在前(qian)級(ji)(ji)電(dian)(dian)(dian)路(lu)(lu)中(zhong)，應檢查(cha)信號輸(shu)(shu)(shu)入插(cha)頭與(yu)插(cha)座(zuo)、轉(zhuan)(zhuan)換開(kai)(kai)關、電(dian)(dian)(dian)位器等是(shi)否接觸(chu)(chu)不(bu)良，耦合(he)電(dian)(dian)(dian)容有無(wu)虛焊(han)、漏電(dian)(dian)(dian)等。后級(ji)(ji)放(fang)大電(dian)(dian)(dian)路(lu)(lu)應檢查(cha)繼電(dian)(dian)(dian)器觸(chu)(chu)點是(shi)否氧化、輸(shu)(shu)(shu) 入耦合(he)電(dian)(dian)(dian)容有無(wu)漏電(dian)(dian)(dian)或接觸(chu)(chu)不(bu)良。另外(wai)，后級(ji)(ji)電(dian)(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)差分(fen)輸(shu)(shu)(shu)入管(guan)或恒流管(guan)軟擊穿，也(ye)會產生類似電(dian)(dian)(dian)火花的(de)(de)“咔咔”噪聲(sheng)。白噪聲(sheng)是(shi)指無(wu)規則的(de)(de)連(lian)續“沙(sha)沙(sha)”聲(sheng)，通常(chang)是(shi)由(you)前(qian)、后級(ji)(ji)放(fang)大電(dian)(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)輸(shu)(shu)(shu)入級(ji)(ji)晶體管(guan)、場效應管(guan)或運放(fang)集成電(dian)(dian)(dian)路(lu)(lu)的(de)(de)性能不(bu)良產生的(de)(de)本底噪聲(sheng)，檢修時(shi)，可用(yong)同規格的(de)(de)元件代換試之。

三、音量(liang)輕

專業中文字幕日韓歐美一區二區三區: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)上各部分均正常，應判斷出(chu)故障是在(zai)前(qian)級(ji)(ji)(ji)還是在(zai)后級(ji)(ji)(ji)電路(lu)(lu)(lu)(lu)。對(dui)于某一個(ge)聲道(dao)音(yin)輕，可將其前(qian)級(ji)(ji)(ji)電路(lu)(lu)(lu)(lu)輸(shu)出(chu)的(de)(de)信號交換輸(shu)入到(dao)另一聲道(dao)的(de)(de)后級(ji)(ji)(ji)電路(lu)(lu)(lu)(lu)，若音(yin)箱(xiang)的(de)(de)聲音(yin)大小不(bu)變(bian)，則(ze)故障在(zai)后級(ji)(ji)(ji)電路(lu)(lu)(lu)(lu)；反之，故障在(zai)前(qian)級(ji)(ji)(ji)電路(lu)(lu)(lu)(lu)。后級(ji)(ji)(ji)放大電路(lu)(lu)(lu)(lu)造成的(de)(de)音(yin)輕，主要有輸(shu)出(chu)功(gong)率不(bu)足(zu)和增益(yi)不(bu)夠兩種原(yuan)因(yin)。可用適當加大輸(shu)入信號(例如將收錄機輸(shu)出(chu)給(gei)揚(yang)聲器的(de)(de)信號直接(jie)加至后級(ji)(ji)(ji)功(gong)放電路(lu)(lu)(lu)(lu)的(de)(de)輸(shu)入端，改變(bian)收錄機的(de)(de)音(yin)量(liang)，觀察功(gong)放輸(shu)出(chu)的(de)(de)變(bian)化)的(de)(de)方法(fa)來判斷是哪種原(yuan)因(yin)引起的(de)(de)。

若(ruo)加(jia)大(da)(da)(da)輸入(ru)信號(hao)后(hou)，輸出(chu)(chu)的聲(sheng)音足夠(gou)大(da)(da)(da)，說(shuo)(shuo)明功(gong)(gong)放(fang)輸出(chu)(chu)功(gong)(gong)率(lv)足夠(gou)，只是增(zeng)益(yi)降低(di)，應(ying)著重檢(jian)(jian)查(cha)(cha)(cha)繼電(dian)(dian)(dian)(dian)器(qi)(qi)觸點有(you)無(wu)接觸電(dian)(dian)(dian)(dian)阻(zu)(zu)增(zeng)大(da)(da)(da)、輸入(ru)耦合電(dian)(dian)(dian)(dian)容容量減(jian)小、隔離電(dian)(dian)(dian)(dian)阻(zu)(zu)阻(zu)(zu)值(zhi)(zhi)增(zeng)大(da)(da)(da)、負(fu)反(fan)(fan)饋電(dian)(dian)(dian)(dian)容容量變(bian)(bian)小或(huo)(huo)(huo)(huo)開(kai)路、負(fu)反(fan)(fan)饋電(dian)(dian)(dian)(dian)阻(zu)(zu)阻(zu)(zu)值(zhi)(zhi)增(zeng)大(da)(da)(da)或(huo)(huo)(huo)(huo)開(kai)路等(deng)現(xian)(xian)象(xiang)。若(ruo)加(jia)大(da)(da)(da)輸入(ru)信號(hao)后(hou)，輸出(chu)(chu)的聲(sheng)音出(chu)(chu)現(xian)(xian)失(shi)真，音量并無(wu)顯著增(zeng)大(da)(da)(da)，說(shuo)(shuo)明后(hou)級放(fang)大(da)(da)(da)器(qi)(qi)的輸出(chu)(chu)功(gong)(gong)率(lv)不足，應(ying)先檢(jian)(jian)查(cha)(cha)(cha)放(fang)大(da)(da)(da)器(qi)(qi)的正、負(fu)供電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓是否偏低(di)(若(ruo)只是一(yi)個聲(sheng)道音輕(qing)，可(ke)不必檢(jian)(jian)查(cha)(cha)(cha)電(dian)(dian)(dian)(dian)源供電(dian)(dian)(dian)(dian))、功(gong)(gong)率(lv)管或(huo)(huo)(huo)(huo)集成(cheng)電(dian)(dian)(dian)(dian)路的性能(neng)是否變(bian)(bian)差、發(fa)射極電(dian)(dian)(dian)(dian)阻(zu)(zu)阻(zu)(zu)值(zhi)(zhi)有(you)無(wu)變(bian)(bian)大(da)(da)(da)等(deng)。前級電(dian)(dian)(dian)(dian)路中(zhong)轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)(dian)位(wei)器(qi)(qi)所造(zao)成(cheng)的音輕(qing)，采用直觀檢(jian)(jian)查(cha)(cha)(cha)較(jiao)易發(fa)現(xian)(xian)，可(ke)對其進行清(qing)洗或(huo)(huo)(huo)(huo)更換(huan)。如(ru)懷疑某信號(hao)耦合電(dian)(dian)(dian)(dian)容失(shi)效，可(ke)用同(tong)值(zhi)(zhi)電(dian)(dian)(dian)(dian)容并聯試之(zhi)；放(fang)大(da)(da)(da)管或(huo)(huo)(huo)(huo)運(yun)放(fang)集成(cheng)電(dian)(dian)(dian)(dian)路性能(neng)不良，也可(ke)用代換(huan)法檢(jian)(jian)查(cha)(cha)(cha)。另(ling)外(wai)，負(fu)反(fan)(fan)饋元件有(you)問題，也會造(zao)成(cheng)電(dian)(dian)(dian)(dian)路增(zeng)益(yi)下降。