眾所周知，日常(chang)(chang)生活中我(wo)們使用(yong)功(gong)放(fang)(fang)機，時間久(jiu)了之后可(ke)能就會出現各種各樣(yang)的問(wen)題，那么，功(gong)放(fang)(fang)機出現問(wen)題的情況下(xia)應該怎么解(jie)(jie)(jie)決呢(ni)？隔山如隔行，雖然不是所有的人(ren)都能解(jie)(jie)(jie)決的，但是了解(jie)(jie)(jie)一些(xie)相(xiang)關方面(mian)的知識會使你(ni)迎刃而解(jie)(jie)(jie)。下(xia)面(mian)介紹功(gong)放(fang)(fang)機的三種常(chang)(chang)見故障及維修(xiu)方法(fa)。

一、整機(ji)不工作

整機不工作的(de)故障表現為(wei)通(tong)電后放大器無任(ren)(ren)何顯示，各功能鍵均失效(xiao)，也(ye)無任(ren)(ren)何聲音，像未通(tong)電時一樣。

檢修時(shi)首先應(ying)檢查電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)電(dian)(dian)路(lu)(lu)。可用萬(wan)用表測(ce)(ce)量電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)插(cha)頭兩端(duan)的(de)(de)直流電(dian)(dian)阻值(zhi)(電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)開關應(ying)接通(tong))，正常時(shi)應(ying)有數百歐姆的(de)(de)電(dian)(dian)阻值(zhi)。若測(ce)(ce)得阻值(zhi)偏(pian)小(xiao)許多(duo)，且電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)器(qi)(qi)嚴重發熱(re)，說(shuo)明電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)器(qi)(qi)的(de)(de)初(chu)級(ji)回(hui)路(lu)(lu)有局(ju)部短路(lu)(lu)處；若測(ce)(ce)得阻值(zhi)為大，應(ying)檢查保險絲是(shi)否(fou)熔斷、變壓(ya)(ya)器(qi)(qi)初(chu)級(ji)繞(rao)組是(shi)否(fou)開路(lu)(lu)、電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)線(xian)與插(cha)頭之間有無斷線(xian)。有的(de)(de)機器(qi)(qi)增加了溫度保護裝置，在電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)器(qi)(qi)的(de)(de)初(chu)級(ji)回(hui)路(lu)(lu)中(zhong)接人了電(dian)(dian)流保險絲(通(tong)常安裝在電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)器(qi)(qi)內(nei)部，將(jiang)變壓(ya)(ya)器(qi)(qi)外部的(de)(de)絕緣紙去掉即(ji)可見(jian)到)，它(ta)損壞后也(ye)會(hui)使(shi)電(dian)(dian)源(yuan)(yuan)(yuan)(yuan)(yuan)(yuan)變壓(ya)(ya)器(qi)(qi)初(chu)級(ji)回(hui)路(lu)(lu)開路(lu)(lu)。

日本不卡一區二區三區: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

放大器的噪聲(sheng)有交流聲(sheng)、爆裂聲(sheng)、感(gan)應噪聲(sheng)和白噪聲(sheng)等。

檢修時，應(ying)(ying)先判斷噪聲(sheng)來(lai)自于前(qian)(qian)級還是(shi)來(lai)自于后級電路(lu)(lu)。可把前(qian)(qian)、后級的(de)(de)信號連接(jie)插頭取下，若噪聲(sheng)明顯變小，說明故(gu)障在(zai)前(qian)(qian)級電路(lu)(lu)；反之，故(gu)障在(zai)后級電路(lu)(lu)。交(jiao)流(liu)(liu)聲(sheng)是(shi)指聽(ting)感低沉(chen)、單(dan)調而穩定(ding)的(de)(de)100Hz交(jiao)流(liu)(liu)哼聲(sheng)，主要是(shi)電源(yuan)部分濾波(bo)(bo)不(bu)良所致(zhi)，應(ying)(ying)著重檢查電源(yuan)整流(liu)(liu)、濾波(bo)(bo)和穩壓元件有無(wu)損(sun)壞(huai)。前(qian)(qian)、后級放大(da)電路(lu)(lu)電源(yuan)端(duan)的(de)(de)退耦電容虛(xu)焊或失效，也會產生一種類似交(jiao)流(liu)(liu)聲(sheng)的(de)(de)低頻振(zhen)蕩噪聲(sheng)。

感應噪聲(sheng)(sheng)(sheng)(sheng)是(shi)(shi)成分較(jiao)復(fu)雜且刺耳的交流(liu)聲(sheng)(sheng)(sheng)(sheng)，主要是(shi)(shi)前(qian)級(ji)電(dian)(dian)(dian)(dian)路(lu)中(zhong)的轉(zhuan)換(huan)開(kai)關(guan)(guan)、電(dian)(dian)(dian)(dian)位(wei)(wei)器(qi)接地不良或信號連線屏蔽(bi)不良所(suo)致。爆裂聲(sheng)(sheng)(sheng)(sheng)是(shi)(shi)指(zhi)間(jian)斷的“劈啪(pa)”、“咔(ka)(ka)咔(ka)(ka)”聲(sheng)(sheng)(sheng)(sheng)，在(zai)前(qian)級(ji)電(dian)(dian)(dian)(dian)路(lu)中(zhong)，應檢查信號輸(shu)入(ru)插頭與插座、轉(zhuan)換(huan)開(kai)關(guan)(guan)、電(dian)(dian)(dian)(dian)位(wei)(wei)器(qi)等是(shi)(shi)否接觸不良，耦合電(dian)(dian)(dian)(dian)容有無(wu)虛(xu)焊、漏電(dian)(dian)(dian)(dian)等。后級(ji)放(fang)大電(dian)(dian)(dian)(dian)路(lu)應檢查繼(ji)電(dian)(dian)(dian)(dian)器(qi)觸點是(shi)(shi)否氧化(hua)、輸(shu) 入(ru)耦合電(dian)(dian)(dian)(dian)容有無(wu)漏電(dian)(dian)(dian)(dian)或接觸不良。另外(wai)，后級(ji)電(dian)(dian)(dian)(dian)路(lu)中(zhong)的差分輸(shu)入(ru)管或恒流(liu)管軟擊穿，也會產(chan)生類似(si)電(dian)(dian)(dian)(dian)火花(hua)的“咔(ka)(ka)咔(ka)(ka)”噪聲(sheng)(sheng)(sheng)(sheng)。白噪聲(sheng)(sheng)(sheng)(sheng)是(shi)(shi)指(zhi)無(wu)規(gui)則的連續“沙沙”聲(sheng)(sheng)(sheng)(sheng)，通常是(shi)(shi)由(you)前(qian)、后級(ji)放(fang)大電(dian)(dian)(dian)(dian)路(lu)中(zhong)的輸(shu)入(ru)級(ji)晶(jing)體管、場效(xiao)應管或運放(fang)集(ji)成電(dian)(dian)(dian)(dian)路(lu)的性能不良產(chan)生的本底噪聲(sheng)(sheng)(sheng)(sheng)，檢修時，可(ke)用同規(gui)格的元件(jian)代換(huan)試之。

三、音量輕

專業日本不卡一區二區三區: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。

若以上(shang)各部分均正常，應(ying)判(pan)斷(duan)出(chu)(chu)(chu)故(gu)(gu)障是(shi)在(zai)(zai)前級(ji)還是(shi)在(zai)(zai)后級(ji)電(dian)(dian)(dian)(dian)路(lu)(lu)。對于某一個(ge)聲(sheng)道(dao)音輕(qing)，可將其前級(ji)電(dian)(dian)(dian)(dian)路(lu)(lu)輸出(chu)(chu)(chu)的(de)(de)(de)(de)(de)信(xin)號(hao)(hao)交(jiao)換輸入到另一聲(sheng)道(dao)的(de)(de)(de)(de)(de)后級(ji)電(dian)(dian)(dian)(dian)路(lu)(lu)，若音箱的(de)(de)(de)(de)(de)聲(sheng)音大小不(bu)變(bian)，則(ze)故(gu)(gu)障在(zai)(zai)后級(ji)電(dian)(dian)(dian)(dian)路(lu)(lu)；反之(zhi)，故(gu)(gu)障在(zai)(zai)前級(ji)電(dian)(dian)(dian)(dian)路(lu)(lu)。后級(ji)放大電(dian)(dian)(dian)(dian)路(lu)(lu)造成的(de)(de)(de)(de)(de)音輕(qing)，主要有輸出(chu)(chu)(chu)功率不(bu)足(zu)和增(zeng)益不(bu)夠兩種原(yuan)(yuan)因。可用適當加(jia)大輸入信(xin)號(hao)(hao)(例如將收錄機(ji)輸出(chu)(chu)(chu)給揚聲(sheng)器(qi)的(de)(de)(de)(de)(de)信(xin)號(hao)(hao)直接加(jia)至后級(ji)功放電(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)(de)(de)(de)輸入端，改變(bian)收錄機(ji)的(de)(de)(de)(de)(de)音量，觀察功放輸出(chu)(chu)(chu)的(de)(de)(de)(de)(de)變(bian)化)的(de)(de)(de)(de)(de)方法來判(pan)斷(duan)是(shi)哪種原(yuan)(yuan)因引起的(de)(de)(de)(de)(de)。

若加大(da)(da)輸入(ru)信號(hao)后，輸出的聲音(yin)足(zu)夠大(da)(da)，說明功(gong)放(fang)輸出功(gong)率(lv)足(zu)夠，只是(shi)(shi)增(zeng)益降低，應著重(zhong)檢(jian)查(cha)(cha)繼電(dian)(dian)(dian)(dian)(dian)器(qi)觸(chu)點有(you)無(wu)接觸(chu)電(dian)(dian)(dian)(dian)(dian)阻(zu)增(zeng)大(da)(da)、輸入(ru)耦合(he)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)阻(zu)值增(zeng)大(da)(da)、負反饋(kui)(kui)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)容(rong)(rong)量(liang)變(bian)小或(huo)開(kai)路(lu)、負反饋(kui)(kui)電(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值增(zeng)大(da)(da)或(huo)開(kai)路(lu)等(deng)現(xian)(xian)象。若加大(da)(da)輸入(ru)信號(hao)后，輸出的聲音(yin)出現(xian)(xian)失真，音(yin)量(liang)并無(wu)顯著增(zeng)大(da)(da)，說明后級(ji)放(fang)大(da)(da)器(qi)的輸出功(gong)率(lv)不(bu)足(zu)，應先檢(jian)查(cha)(cha)放(fang)大(da)(da)器(qi)的正、負供電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓是(shi)(shi)否偏低(若只是(shi)(shi)一個聲道(dao)音(yin)輕，可(ke)(ke)不(bu)必檢(jian)查(cha)(cha)電(dian)(dian)(dian)(dian)(dian)源供電(dian)(dian)(dian)(dian)(dian))、功(gong)率(lv)管(guan)或(huo)集(ji)(ji)成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)的性(xing)能是(shi)(shi)否變(bian)差、發射極電(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值有(you)無(wu)變(bian)大(da)(da)等(deng)。前級(ji)電(dian)(dian)(dian)(dian)(dian)路(lu)中轉換(huan)開(kai)關(guan)、電(dian)(dian)(dian)(dian)(dian)位器(qi)所造(zao)成(cheng)的音(yin)輕，采用直觀檢(jian)查(cha)(cha)較易發現(xian)(xian)，可(ke)(ke)對其(qi)進行清洗或(huo)更換(huan)。如懷疑(yi)某(mou)信號(hao)耦合(he)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)失效，可(ke)(ke)用同值電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)并聯(lian)試之(zhi)；放(fang)大(da)(da)管(guan)或(huo)運放(fang)集(ji)(ji)成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)性(xing)能不(bu)良，也可(ke)(ke)用代(dai)換(huan)法檢(jian)查(cha)(cha)。另外，負反饋(kui)(kui)元(yuan)件(jian)有(you)問題，也會造(zao)成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)增(zeng)益下(xia)降。