眾所周知，日常生(sheng)活(huo)中我們使用(yong)功放(fang)機，時間(jian)久了之后可能就會(hui)(hui)出現各種各樣的問題，那么，功放(fang)機出現問題的情況下應該怎(zen)么解決(jue)呢？隔山如(ru)隔行，雖然不是(shi)所有的人都能解決(jue)的，但(dan)是(shi)了解一些(xie)相關方面的知識(shi)會(hui)(hui)使你(ni)迎刃而(er)解。下面介紹(shao)功放(fang)機的三種常見故(gu)障及維修方法。

一、整機不工作

整機(ji)不工作(zuo)的故障表現為(wei)通電(dian)后(hou)放大器無任何顯(xian)示，各功能鍵均失效，也無任何聲音，像未通電(dian)時(shi)一(yi)樣。

檢修時(shi)首先(xian)應(ying)檢查(cha)電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)路(lu)(lu)。可用萬用表測量電(dian)(dian)(dian)(dian)源(yuan)插頭兩端的(de)(de)直流電(dian)(dian)(dian)(dian)阻(zu)值(zhi)(電(dian)(dian)(dian)(dian)源(yuan)開(kai)關(guan)應(ying)接通(tong))，正常時(shi)應(ying)有數百歐(ou)姆(mu)的(de)(de)電(dian)(dian)(dian)(dian)阻(zu)值(zhi)。若(ruo)測得阻(zu)值(zhi)偏小許(xu)多，且電(dian)(dian)(dian)(dian)源(yuan)變(bian)(bian)壓(ya)器(qi)嚴重發熱，說明(ming)電(dian)(dian)(dian)(dian)源(yuan)變(bian)(bian)壓(ya)器(qi)的(de)(de)初級(ji)回(hui)路(lu)(lu)有局(ju)部(bu)短路(lu)(lu)處；若(ruo)測得阻(zu)值(zhi)為大(da)，應(ying)檢查(cha)保險絲是否熔斷、變(bian)(bian)壓(ya)器(qi)初級(ji)繞組是否開(kai)路(lu)(lu)、電(dian)(dian)(dian)(dian)源(yuan)線與插頭之間有無斷線。有的(de)(de)機器(qi)增加了溫度保護裝置，在(zai)電(dian)(dian)(dian)(dian)源(yuan)變(bian)(bian)壓(ya)器(qi)的(de)(de)初級(ji)回(hui)路(lu)(lu)中(zhong)接人了電(dian)(dian)(dian)(dian)流保險絲(通(tong)常安(an)裝在(zai)電(dian)(dian)(dian)(dian)源(yuan)變(bian)(bian)壓(ya)器(qi)內(nei)部(bu)，將變(bian)(bian)壓(ya)器(qi)外部(bu)的(de)(de)絕緣紙去掉即可見到)，它損壞后也會使電(dian)(dian)(dian)(dian)源(yuan)變(bian)(bian)壓(ya)器(qi)初級(ji)回(hui)路(lu)(lu)開(kai)路(lu)(lu)。

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、噪聲大

放大器的(de)噪(zao)(zao)聲有交流聲、爆裂(lie)聲、感應噪(zao)(zao)聲和(he)白噪(zao)(zao)聲等。

檢修時，應先判斷噪聲(sheng)來(lai)自(zi)于前(qian)級還(huan)是(shi)來(lai)自(zi)于后級電(dian)路(lu)(lu)。可(ke)把前(qian)、后級的(de)信號連接插頭取下，若(ruo)噪聲(sheng)明顯(xian)變小(xiao)，說明故障(zhang)在前(qian)級電(dian)路(lu)(lu)；反之，故障(zhang)在后級電(dian)路(lu)(lu)。交流(liu)聲(sheng)是(shi)指聽感低沉、單調而穩定的(de)100Hz交流(liu)哼聲(sheng)，主要是(shi)電(dian)源(yuan)部分濾(lv)波(bo)不良所致(zhi)，應著(zhu)重檢查電(dian)源(yuan)整流(liu)、濾(lv)波(bo)和穩壓元件有無損壞(huai)。前(qian)、后級放大電(dian)路(lu)(lu)電(dian)源(yuan)端的(de)退耦(ou)電(dian)容虛(xu)焊或失效，也(ye)會(hui)產生一(yi)種(zhong)類似交流(liu)聲(sheng)的(de)低頻振(zhen)蕩噪聲(sheng)。

感應(ying)噪(zao)聲(sheng)(sheng)是(shi)(shi)成分較復雜且刺(ci)耳的(de)交(jiao)流(liu)聲(sheng)(sheng)，主要是(shi)(shi)前(qian)級(ji)(ji)(ji)電(dian)(dian)(dian)路中的(de)轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)位器接地(di)不(bu)良(liang)或(huo)信號連線屏蔽不(bu)良(liang)所致。爆裂聲(sheng)(sheng)是(shi)(shi)指(zhi)(zhi)間(jian)斷(duan)的(de)“劈(pi)啪(pa)”、“咔咔”聲(sheng)(sheng)，在(zai)前(qian)級(ji)(ji)(ji)電(dian)(dian)(dian)路中，應(ying)檢查信號輸(shu)入(ru)插頭與插座、轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)位器等是(shi)(shi)否(fou)接觸不(bu)良(liang)，耦(ou)合電(dian)(dian)(dian)容(rong)(rong)有無(wu)虛(xu)焊、漏電(dian)(dian)(dian)等。后級(ji)(ji)(ji)放(fang)大電(dian)(dian)(dian)路應(ying)檢查繼(ji)電(dian)(dian)(dian)器觸點是(shi)(shi)否(fou)氧化、輸(shu) 入(ru)耦(ou)合電(dian)(dian)(dian)容(rong)(rong)有無(wu)漏電(dian)(dian)(dian)或(huo)接觸不(bu)良(liang)。另外，后級(ji)(ji)(ji)電(dian)(dian)(dian)路中的(de)差分輸(shu)入(ru)管(guan)(guan)或(huo)恒(heng)流(liu)管(guan)(guan)軟擊(ji)穿，也會(hui)產生類似電(dian)(dian)(dian)火花(hua)的(de)“咔咔”噪(zao)聲(sheng)(sheng)。白噪(zao)聲(sheng)(sheng)是(shi)(shi)指(zhi)(zhi)無(wu)規則的(de)連續“沙沙”聲(sheng)(sheng)，通(tong)常是(shi)(shi)由(you)前(qian)、后級(ji)(ji)(ji)放(fang)大電(dian)(dian)(dian)路中的(de)輸(shu)入(ru)級(ji)(ji)(ji)晶體(ti)管(guan)(guan)、場效(xiao)應(ying)管(guan)(guan)或(huo)運放(fang)集成電(dian)(dian)(dian)路的(de)性能(neng)不(bu)良(liang)產生的(de)本底噪(zao)聲(sheng)(sheng)，檢修時，可(ke)用同(tong)規格的(de)元件代換(huan)試之。

三、音(yin)量輕

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(ruo)以上各部分(fen)均正常，應判(pan)斷出(chu)故(gu)(gu)障(zhang)是(shi)(shi)在(zai)前級(ji)(ji)(ji)還是(shi)(shi)在(zai)后(hou)級(ji)(ji)(ji)電(dian)(dian)路(lu)。對于某一個(ge)聲(sheng)道(dao)音(yin)輕，可將(jiang)其前級(ji)(ji)(ji)電(dian)(dian)路(lu)輸(shu)出(chu)的(de)(de)(de)信號(hao)交(jiao)換輸(shu)入到另一聲(sheng)道(dao)的(de)(de)(de)后(hou)級(ji)(ji)(ji)電(dian)(dian)路(lu)，若(ruo)音(yin)箱的(de)(de)(de)聲(sheng)音(yin)大(da)小不變(bian)，則故(gu)(gu)障(zhang)在(zai)后(hou)級(ji)(ji)(ji)電(dian)(dian)路(lu)；反之，故(gu)(gu)障(zhang)在(zai)前級(ji)(ji)(ji)電(dian)(dian)路(lu)。后(hou)級(ji)(ji)(ji)放(fang)大(da)電(dian)(dian)路(lu)造成的(de)(de)(de)音(yin)輕，主要有輸(shu)出(chu)功(gong)(gong)率不足和增益(yi)不夠(gou)兩種(zhong)原因。可用適當加(jia)大(da)輸(shu)入信號(hao)(例(li)如(ru)將(jiang)收(shou)錄(lu)(lu)機(ji)輸(shu)出(chu)給揚(yang)聲(sheng)器的(de)(de)(de)信號(hao)直接加(jia)至后(hou)級(ji)(ji)(ji)功(gong)(gong)放(fang)電(dian)(dian)路(lu)的(de)(de)(de)輸(shu)入端，改變(bian)收(shou)錄(lu)(lu)機(ji)的(de)(de)(de)音(yin)量，觀察功(gong)(gong)放(fang)輸(shu)出(chu)的(de)(de)(de)變(bian)化(hua))的(de)(de)(de)方法來判(pan)斷是(shi)(shi)哪種(zhong)原因引起(qi)的(de)(de)(de)。

若加大(da)(da)(da)(da)輸入(ru)信號(hao)后，輸出的(de)(de)聲音足(zu)夠(gou)大(da)(da)(da)(da)，說(shuo)明(ming)功放(fang)輸出功率足(zu)夠(gou)，只是(shi)(shi)(shi)增(zeng)(zeng)益降低，應著(zhu)重檢(jian)(jian)(jian)查(cha)繼電(dian)(dian)(dian)器(qi)(qi)觸點有(you)無接觸電(dian)(dian)(dian)阻(zu)增(zeng)(zeng)大(da)(da)(da)(da)、輸入(ru)耦合電(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)減小(xiao)、隔(ge)離電(dian)(dian)(dian)阻(zu)阻(zu)值增(zeng)(zeng)大(da)(da)(da)(da)、負反饋(kui)電(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)變小(xiao)或(huo)開(kai)路(lu)、負反饋(kui)電(dian)(dian)(dian)阻(zu)阻(zu)值增(zeng)(zeng)大(da)(da)(da)(da)或(huo)開(kai)路(lu)等現(xian)(xian)象(xiang)。若加大(da)(da)(da)(da)輸入(ru)信號(hao)后，輸出的(de)(de)聲音出現(xian)(xian)失真，音量(liang)并(bing)無顯著(zhu)增(zeng)(zeng)大(da)(da)(da)(da)，說(shuo)明(ming)后級放(fang)大(da)(da)(da)(da)器(qi)(qi)的(de)(de)輸出功率不足(zu)，應先檢(jian)(jian)(jian)查(cha)放(fang)大(da)(da)(da)(da)器(qi)(qi)的(de)(de)正(zheng)、負供電(dian)(dian)(dian)電(dian)(dian)(dian)壓是(shi)(shi)(shi)否(fou)偏(pian)低(若只是(shi)(shi)(shi)一個聲道音輕，可(ke)不必檢(jian)(jian)(jian)查(cha)電(dian)(dian)(dian)源供電(dian)(dian)(dian))、功率管(guan)或(huo)集(ji)成(cheng)(cheng)電(dian)(dian)(dian)路(lu)的(de)(de)性能(neng)是(shi)(shi)(shi)否(fou)變差、發(fa)射極(ji)電(dian)(dian)(dian)阻(zu)阻(zu)值有(you)無變大(da)(da)(da)(da)等。前級電(dian)(dian)(dian)路(lu)中(zhong)轉換(huan)開(kai)關、電(dian)(dian)(dian)位器(qi)(qi)所造成(cheng)(cheng)的(de)(de)音輕，采(cai)用(yong)(yong)直觀檢(jian)(jian)(jian)查(cha)較易(yi)發(fa)現(xian)(xian)，可(ke)對(dui)其進行清洗或(huo)更換(huan)。如懷疑某信號(hao)耦合電(dian)(dian)(dian)容(rong)(rong)失效，可(ke)用(yong)(yong)同值電(dian)(dian)(dian)容(rong)(rong)并(bing)聯試之(zhi)；放(fang)大(da)(da)(da)(da)管(guan)或(huo)運放(fang)集(ji)成(cheng)(cheng)電(dian)(dian)(dian)路(lu)性能(neng)不良，也(ye)(ye)可(ke)用(yong)(yong)代(dai)換(huan)法(fa)檢(jian)(jian)(jian)查(cha)。另外，負反饋(kui)元件有(you)問題，也(ye)(ye)會造成(cheng)(cheng)電(dian)(dian)(dian)路(lu)增(zeng)(zeng)益下降。