眾(zhong)所周知(zhi)，日常(chang)生(sheng)活中我們使用功(gong)放機，時間久(jiu)了(le)之后可能(neng)就會(hui)出(chu)現各(ge)種(zhong)各(ge)樣的(de)問(wen)題(ti)，那么(me)，功(gong)放機出(chu)現問(wen)題(ti)的(de)情況下應該怎(zen)么(me)解(jie)決(jue)呢(ni)？隔山如隔行，雖(sui)然不是(shi)所有的(de)人都能(neng)解(jie)決(jue)的(de)，但是(shi)了(le)解(jie)一些(xie)相(xiang)關方面的(de)知(zhi)識(shi)會(hui)使你迎刃而解(jie)。下面介紹(shao)功(gong)放機的(de)三(san)種(zhong)常(chang)見故障及維修方法。

一、整機不工(gong)作

整機不工作的故障表現為通(tong)電(dian)(dian)后放大器無任(ren)何(he)(he)顯示，各功能鍵均失效(xiao)，也無任(ren)何(he)(he)聲音(yin)，像(xiang)未通(tong)電(dian)(dian)時一樣。

檢(jian)(jian)修時首先應(ying)檢(jian)(jian)查電(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)。可用(yong)萬用(yong)表測量電(dian)(dian)(dian)(dian)源(yuan)(yuan)插頭(tou)兩(liang)端的(de)直流(liu)電(dian)(dian)(dian)(dian)阻(zu)值(zhi)(電(dian)(dian)(dian)(dian)源(yuan)(yuan)開(kai)關應(ying)接(jie)通)，正常(chang)時應(ying)有數百歐姆的(de)電(dian)(dian)(dian)(dian)阻(zu)值(zhi)。若測得阻(zu)值(zhi)偏小許(xu)多，且電(dian)(dian)(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)(qi)嚴(yan)重發熱，說明電(dian)(dian)(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)(qi)的(de)初級(ji)(ji)回路(lu)(lu)(lu)有局部(bu)短(duan)路(lu)(lu)(lu)處(chu)；若測得阻(zu)值(zhi)為大，應(ying)檢(jian)(jian)查保險絲(si)是否(fou)熔斷、變壓(ya)器(qi)(qi)初級(ji)(ji)繞組是否(fou)開(kai)路(lu)(lu)(lu)、電(dian)(dian)(dian)(dian)源(yuan)(yuan)線與插頭(tou)之間有無斷線。有的(de)機器(qi)(qi)增加了溫(wen)度保護裝置(zhi)，在電(dian)(dian)(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)(qi)的(de)初級(ji)(ji)回路(lu)(lu)(lu)中接(jie)人了電(dian)(dian)(dian)(dian)流(liu)保險絲(si)(通常(chang)安裝在電(dian)(dian)(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)(qi)內部(bu)，將變壓(ya)器(qi)(qi)外部(bu)的(de)絕緣紙去掉即可見到(dao))，它損壞(huai)后也會使電(dian)(dian)(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)(qi)初級(ji)(ji)回路(lu)(lu)(lu)開(kai)路(lu)(lu)(lu)。

國產精品免費一區二區三區四區: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

放大器的噪聲有交流聲、爆裂聲、感應噪聲和白噪聲等。

檢(jian)修時，應(ying)先(xian)判(pan)斷(duan)噪(zao)聲來自(zi)于前級(ji)(ji)還是(shi)來自(zi)于后級(ji)(ji)電路(lu)(lu)(lu)。可(ke)把前、后級(ji)(ji)的(de)信(xin)號連接插頭取下，若(ruo)噪(zao)聲明顯變小(xiao)，說明故障在(zai)(zai)前級(ji)(ji)電路(lu)(lu)(lu)；反(fan)之，故障在(zai)(zai)后級(ji)(ji)電路(lu)(lu)(lu)。交(jiao)(jiao)(jiao)流聲是(shi)指(zhi)聽(ting)感低沉、單調而(er)穩(wen)定的(de)100Hz交(jiao)(jiao)(jiao)流哼聲，主要(yao)是(shi)電源部分濾波不良所致，應(ying)著(zhu)重檢(jian)查電源整流、濾波和穩(wen)壓(ya)元件有(you)無損壞。前、后級(ji)(ji)放(fang)大電路(lu)(lu)(lu)電源端(duan)的(de)退耦電容虛焊或失效，也(ye)會產生一種類似交(jiao)(jiao)(jiao)流聲的(de)低頻振蕩(dang)噪(zao)聲。

感應(ying)噪(zao)聲(sheng)(sheng)是(shi)(shi)成分較復(fu)雜(za)且刺耳的(de)交流(liu)聲(sheng)(sheng)，主(zhu)要是(shi)(shi)前級(ji)電(dian)(dian)(dian)路中的(de)轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)位器(qi)接(jie)地(di)不(bu)(bu)良或(huo)(huo)信(xin)號(hao)連(lian)線(xian)屏蔽(bi)不(bu)(bu)良所(suo)致。爆裂聲(sheng)(sheng)是(shi)(shi)指間斷(duan)的(de)“劈(pi)啪”、“咔咔”聲(sheng)(sheng)，在前級(ji)電(dian)(dian)(dian)路中，應(ying)檢查(cha)信(xin)號(hao)輸(shu)(shu)入插(cha)(cha)頭與插(cha)(cha)座、轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)位器(qi)等是(shi)(shi)否接(jie)觸不(bu)(bu)良，耦合(he)電(dian)(dian)(dian)容有無虛焊(han)、漏電(dian)(dian)(dian)等。后級(ji)放(fang)大電(dian)(dian)(dian)路應(ying)檢查(cha)繼電(dian)(dian)(dian)器(qi)觸點(dian)是(shi)(shi)否氧化(hua)、輸(shu)(shu) 入耦合(he)電(dian)(dian)(dian)容有無漏電(dian)(dian)(dian)或(huo)(huo)接(jie)觸不(bu)(bu)良。另外，后級(ji)電(dian)(dian)(dian)路中的(de)差分輸(shu)(shu)入管(guan)或(huo)(huo)恒流(liu)管(guan)軟擊(ji)穿，也(ye)會產(chan)生類似電(dian)(dian)(dian)火花的(de)“咔咔”噪(zao)聲(sheng)(sheng)。白噪(zao)聲(sheng)(sheng)是(shi)(shi)指無規(gui)則的(de)連(lian)續(xu)“沙沙”聲(sheng)(sheng)，通(tong)常是(shi)(shi)由(you)前、后級(ji)放(fang)大電(dian)(dian)(dian)路中的(de)輸(shu)(shu)入級(ji)晶體(ti)(ti)管(guan)、場(chang)效(xiao)應(ying)管(guan)或(huo)(huo)運放(fang)集成電(dian)(dian)(dian)路的(de)性能不(bu)(bu)良產(chan)生的(de)本(ben)底噪(zao)聲(sheng)(sheng)，檢修時，可用(yong)同(tong)規(gui)格的(de)元件代換(huan)試(shi)之。

三(san)、音量輕

專業國產精品免費一區二區三區四區: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。

若以上各部分均正(zheng)常(chang)，應判斷出(chu)(chu)故障(zhang)是在前級還是在后(hou)級電路(lu)(lu)。對于某一個(ge)聲道音(yin)(yin)(yin)輕，可將其前級電路(lu)(lu)輸(shu)出(chu)(chu)的(de)(de)信(xin)號(hao)交換輸(shu)入到另一聲道的(de)(de)后(hou)級電路(lu)(lu)，若音(yin)(yin)(yin)箱的(de)(de)聲音(yin)(yin)(yin)大小不(bu)變，則故障(zhang)在后(hou)級電路(lu)(lu)；反之，故障(zhang)在前級電路(lu)(lu)。后(hou)級放(fang)大電路(lu)(lu)造成(cheng)的(de)(de)音(yin)(yin)(yin)輕，主要有輸(shu)出(chu)(chu)功率不(bu)足和增益不(bu)夠(gou)兩(liang)種原因。可用(yong)適當加大輸(shu)入信(xin)號(hao)(例如將收(shou)錄機輸(shu)出(chu)(chu)給(gei)揚聲器的(de)(de)信(xin)號(hao)直接(jie)加至后(hou)級功放(fang)電路(lu)(lu)的(de)(de)輸(shu)入端，改變收(shou)錄機的(de)(de)音(yin)(yin)(yin)量，觀(guan)察功放(fang)輸(shu)出(chu)(chu)的(de)(de)變化(hua))的(de)(de)方法來判斷是哪種原因引起的(de)(de)。

若(ruo)(ruo)加大(da)(da)(da)輸(shu)入信(xin)號后(hou)(hou)，輸(shu)出的(de)聲音(yin)足(zu)夠大(da)(da)(da)，說明(ming)功(gong)(gong)放(fang)輸(shu)出功(gong)(gong)率(lv)足(zu)夠，只(zhi)是(shi)增(zeng)益降低，應著(zhu)(zhu)重檢(jian)查(cha)繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)觸點有無接觸電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)增(zeng)大(da)(da)(da)、輸(shu)入耦合(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容容量(liang)減小、隔(ge)離電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)(zhi)增(zeng)大(da)(da)(da)、負反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容容量(liang)變(bian)小或開路(lu)、負反饋(kui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)(zhi)增(zeng)大(da)(da)(da)或開路(lu)等現(xian)(xian)象(xiang)。若(ruo)(ruo)加大(da)(da)(da)輸(shu)入信(xin)號后(hou)(hou)，輸(shu)出的(de)聲音(yin)出現(xian)(xian)失(shi)真，音(yin)量(liang)并(bing)(bing)無顯著(zhu)(zhu)增(zeng)大(da)(da)(da)，說明(ming)后(hou)(hou)級放(fang)大(da)(da)(da)器(qi)的(de)輸(shu)出功(gong)(gong)率(lv)不足(zu)，應先檢(jian)查(cha)放(fang)大(da)(da)(da)器(qi)的(de)正、負供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)否偏低(若(ruo)(ruo)只(zhi)是(shi)一(yi)個聲道(dao)音(yin)輕，可(ke)不必檢(jian)查(cha)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian))、功(gong)(gong)率(lv)管或集(ji)成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)的(de)性(xing)能是(shi)否變(bian)差、發(fa)射極電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)阻(zu)(zu)(zu)值(zhi)(zhi)有無變(bian)大(da)(da)(da)等。前級電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中轉換(huan)開關、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器(qi)所造成的(de)音(yin)輕，采用(yong)直觀檢(jian)查(cha)較(jiao)易發(fa)現(xian)(xian)，可(ke)對(dui)其進行(xing)清洗或更(geng)換(huan)。如(ru)懷疑某(mou)信(xin)號耦合(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容失(shi)效(xiao)，可(ke)用(yong)同(tong)值(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容并(bing)(bing)聯(lian)試之；放(fang)大(da)(da)(da)管或運放(fang)集(ji)成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)性(xing)能不良，也(ye)可(ke)用(yong)代換(huan)法檢(jian)查(cha)。另外，負反饋(kui)元件有問(wen)題(ti)，也(ye)會造成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)增(zeng)益下降。