Cov ntaub ntawv kho mob rau AC fais fab mov
Fault 1: Lub fuse yog cua tshuab
Thaum zoo li no tsis ua hauj lwm tshwm sim, thawj qhib lub hwj huam mov plhaub thiab xyuas seb lub fuse ntawm lub hwj chim mov yog tshuab, thiaj li mus txiav txim ua ntej seb lub inverter Circuit Court ua tsis tau tejyam. Yog tias muaj, nws yog tshwm sim los ntawm peb qhov xwm txheej hauv qab no: tus choj rectifier diode hauv cov khoom siv hluav taws xob tau tawg; lub high-voltage lim electrolytic capacitor yog tawg; lub inverter fais fab hloov raj puas lawm. Lub ntsiab yog vim li cas DC filtering thiab transforming oscillation circuits ua hauj lwm nyob rau hauv high voltage (ntxiv rau 300V) thiab siab tam sim no lub sij hawm ntev, tshwj xeeb tshaj yog thaum lub AC voltage hloov heev thiab cov zis load yog hnyav, qhov txhaum ntawm fuse tshuab yog nquag mus. tshwm sim. Lub DC lim Circuit Court yog tsim los ntawm plaub lub diodes rectifying, ob qhov kev txwv tam sim no ntawm 100KΩ thiab ob lub electrolytic capacitors txog 330μF; qhov hloov dua siab tshiab oscillation Circuit Court yog tsuas yog tsim los ntawm ob lub zog hloov hluav taws xob ntawm tib hom ntsia ntawm tib lub dab dej kub.
Tom qab AC fuse tau tshuab, tua lub hwj chim thiab tshem tawm lub hwj chim ntsaws. Ua ntej, ua tib zoo saib seb qhov zoo li ntawm txhua qhov hluav taws xob tiv thaiv hluav taws xob ntawm lub rooj tsav xwm hluav taws xob tau tawg thiab kub hnyiab lossis cov kab ntawm electrolyte overflowing. Yog tias tsis muaj qhov txawv txav, siv lub multimeter los ntsuas tus nqi ntawm cov khoom siv nkag. Yog tias nws tsawg dua 200KΩ, qhia tau hais tias muaj ib feem luv luv Circuit Court tom qab kawg, thiab tom qab ntawd ntsuas qhov kev tiv thaiv ntawm e thiab c ncej ntawm ob lub zog hloov hluav taws xob sib txuas. Yog tias nws tsawg dua 100KΩ, nws txhais tau tias lub raj hloov pauv puas lawm. Ntsuas qhov kev tiv thaiv rau pem hauv ntej thiab thim rov qab ntawm plaub lub rectifier diodes Thiab qhov kev tiv thaiv ntawm ob qhov kev txwv tam sim no, siv lub multimeter los ntsuas cov nqi thiab kev tso tawm los txiav txim seb nws puas zoo li qub. Tsis tas li ntawd, thaum hloov lub hloov lub raj, yog tias koj nrhiav tsis tau tib yam khoom thiab xaiv ib qho kev hloov, koj yuav tsum tau them sai sai rau lub collector-emitter reverse breakdown voltage Vceo, lub siab tshaj plaws tso cai collector fais fab dissipation pcm, thiab lub collector-base. rov qab breakdown voltage. Qhov tsis sib xws ntawm qhov crossover voltage Vcbo yuav tsum ntau dua lossis sib npaug rau qhov tsis sib xws ntawm qhov qub transistor. Lwm yam uas yuav tsum tau them sai sai rau yog: thaum pom tias muaj qee yam kev puas tsuaj, nws yuav tsum tsis txhob muab tso ncaj qha tom qab hloov, txwv tsis pub cov khoom hloov pauv tuaj yeem raug puas vim lwm cov khoom siv hluav taws xob tseem tsis raug. Nws yog ib qho tsim nyog yuav tsum tau ua kom tiav kev tshuaj xyuas thiab ntsuas ntawm tag nrho cov high-voltage Cheebtsam ntawm cov saum toj no-hais Circuit Court ua ntej lub fuse blown txhaum yuav txiav txim tag nrho.
Fault 2: Tsis muaj DC voltage tso zis los yog tsis ruaj tsis khov voltage tso zis
Kev soj ntsuam yuam kev thiab kev daws teeb meem: Yog tias lub fuse tsis zoo, tsis muaj qhov tso tawm ntawm DC voltage ntawm txhua qib raws li kev thauj khoom. Cov laj thawj yog: qhib Circuit Court thiab luv Circuit Court nyob rau hauv lub hwj chim mov, tsis ua hauj lwm ntawm overvoltage thiab overcurrent tiv thaiv Circuit Court, thiab tsis ua hauj lwm ntawm lub oscillation Circuit Court. Lub load ntawm lub hwj chim mov yog hnyav heev, lub rectifier diode nyob rau hauv lub high-frequency rectifier lim Circuit Court yog tawg, thiab lub lim capacitor leaks, thiab lwm yam. Txoj kev kho yog: siv ib tug multimeter los ntsuas cov av tiv thaiv ntawm lub system board. ntxiv rau 5V fais fab mov. Yog tias nws loj dua 0.8Ω, nws txhais tau hais tias tsis muaj luv luv Circuit Court ntawm lub rooj tsavxwm; hloov lub configuration ntawm microcomputer mus rau qhov tsawg kawg nkaus, uas yog, tsuas yog lub ntsiab board, lub hwj chim mov, thiab buzzer nyob rau hauv lub tshuab. Ntsuas qhov DC voltage ntawm txhua qhov tso zis hluav taws xob, yog tias tseem tsis muaj qhov tso tawm, nws txhais tau tias qhov txhaum yog nyob rau hauv kev tswj Circuit Court ntawm microcomputer fais fab mov. Kev tswj xyuas hluav taws xob feem ntau yog tsim los ntawm kev sib txuas hluav taws xob hloov hluav taws xob (TL-496, GS3424, thiab lwm yam) thiab kev tiv thaiv hluav taws xob overvoltage. Txawm hais tias qhov kev tswj xyuas Circuit Court ua haujlwm ib txwm muaj feem cuam tshuam ncaj qha rau seb qhov DC qhov hluav taws xob yog qhov tso tawm lossis tsis. Lub overvoltage tiv thaiv Circuit Court yog tsuas yog tsim los ntawm tsawg-power triode los yog thyristor thiab lwm yam Cheebtsam. Ib tug multimeter tuaj yeem siv los ntsuas seb lub triode puas tawg (yog tias nws yog thyristor, nws yuav tsum tau soldered thiab ntsuas), thiab seb puas muaj feem cuam tshuam thiab capacitance puas. Thaum kawg, siv lub multimeter los ntsuas ntsuas seb puas yog lub rectifier diode thiab low-voltage filter capacitor nyob rau hauv lub high-frequency lim circuit puas lawm.
Fault 3: Lub hwj huam mov muaj cov zis, tab sis tsis muaj cov zaub thaum nws qhib
Kev soj ntsuam yuam kev thiab kev daws teeb meem: Qhov ua tau ntawm qhov ua txhaum no yog qhov ncua sij hawm ntawm kev rov pib teeb liab tawm tswv yim los ntawm "pOWERGOOD" tsis txaus, lossis tsis muaj qhov tso tawm los ntawm "pOWERGOOD".
Tom qab pib, siv lub voltmeter los ntsuas qhov tso zis davhlau ya nyob twg ntawm "pOWERGOOD" (txuas mus rau tus pin 1 ntawm lub hwj chim ntsaws). Yog tias tsis muaj ntxiv 5V tso zis, xyuas cov khoom ncua sij hawm. Yog hais tias muaj ntxiv 5V tso zis, hloov lub ncua sij hawm capacitor ntawm ncua Circuit Court. Ua tau.
Fault 4: Tsis muaj zog load peev xwm
Fault Analysis thiab Elimination: Lub hwj huam mov tuaj yeem ua haujlwm ib txwm thaum nws tsuas yog muab lub zog rau lub motherboard thiab floppy drive. Thaum lub hard disk thiab CD-ROM drive txuas nrog, lub vijtsam tig dawb thiab tsis tuaj yeem ua haujlwm ib txwm. Cov laj thawj yog vim li cas: qhov chaw ua haujlwm ntawm lub transistor tsis raug xaiv kom raug, lub siab-voltage lim capacitor leaks lossis puas, Zener diode heats li thiab leaks, rectifier diode puas, thiab lwm yam.
Hloov cov transistors nyob rau hauv lub oscillating circuit kom nce qhov nce, los yog nce qhov chaw khiav hauj lwm ntawm cov transistors. Tom qab kuaj pom qhov teeb meem nrog lub multimeter, hloov lub thyristor, Zener diode, high-voltage lim capacitor lossis rectifier diode.
Fault 5: Tsis muaj DC tso zis
Cov khoom uas tej zaum yuav faulty yog: lub fuse yog cua tshuab, lub converter tsis ua hauj lwm, thiab tswj Circuit Court yog faulty. Qhib lub thawv fais fab thiab pom tias lub fuse raug tshem tawm. Raws li cov neeg siv tswv yim, lub fuse tau raug hloov thiab hlawv ntau zaus. solder lub rectifier diode thiab lub converter fais fab hloov raj, thiab xyuas nrog ib tug multimeter tias txhua yam yog zoo, thiab siv ib tug high-impedance iav los xyuas kom meej tias tsis muaj luv luv Circuit Court ntawm AC input davhlau ya nyob twg. Xyuas tias lub rectifier lim capacitor yog qhov qub. Judging los ntawm lub tshuab fuse, qhov chaw txhaum yuav tsum nyob rau hauv pem hauv ntej ntawm lub ntsiab winding ntawm lub converter, tab sis tsis pom luv luv Circuit Court. Yuav tsum tau rov qab kho qhov qub qub, hloov lub fuse thiab lub zog ntawm qhov kev sim. Qhib lub AC fais fab mov, lub fuse yog tshuab, tam sim ntawd disconnect lub AC fais fab mov rau kev soj ntsuam, lub fuse tube yog burnt dub. Nws tuaj yeem pom tias muaj qhov luv luv luv hauv AC input circuit, disconnect AC input ntawm tus choj rectifier. Ntxiv fuses ntawm ob qho kawg ntawm AC input ntawm tus choj rectifier, thiab txuas ncaj qha mus rau AC fais fab mov. Tig rau lub hwj huam mov, tswj fais fab mov kiv cua tig ib txwm, thiab DC tso zis voltage ntawm txhua qhov kev ntsuam xyuas yog qhov qub. Nws tuaj yeem pom tias qhov chaw txhaum yog nyob rau hauv AC lim Circuit Court, tab sis nws tsis muaj txiaj ntsig los kuaj xyuas nws nrog multimeter. Lub sijhawm no, kuv xav txog lwm txoj hauv kev, thiab tshem tawm ob lub AC lim capacitors los ntawm lwm lub zog los hloov lawv. (Vim tias qhov vuam yog qhov yooj yim, hloov cov capacitors ua ntej.) Kev ntsuas hluav taws xob, DC stabilized fais fab mov ua haujlwm ib txwm. Nws tuaj yeem pom tau tias qhov chaw txhaum yog nyob rau hauv ob lub capacitors, kuaj nrog lub siab-voltage insulator, thiab ib qho ntawm cov capacitors muaj kev puas tsuaj loj.
Fault 6: Lub khoos phis tawj kuaj xyuas tus kheej tom qab pib, thiab khau raj zoo li qub. Thaum lub vijtsam qhia "INSERTSYSTEMDISKINDRIVEAANDPRESSANYKEY", ntxig rau DOS disk, thiab lub floppy drive tsis nyeem lub disk.
Los ntawm kev tshuaj xyuas ntawm qhov tshwm sim txhaum, qhov chaw txhaum yog nyob rau hauv lub floppy disk drive, floppy disk adapter lossis lub system. Tom qab hloov txoj kev, nws tau ua pov thawj tias floppy disk adapter thiab floppy disk tsav ntawm lub tshuab no zoo. Thaum kawg, tshem lub motherboard kom paub tseeb tias nws zoo. Tom qab rov kho qhov qub qub, lub hwj chim rau thiab sim, qhov txhaum tsis tuaj yeem raug tshem tawm. Yog li xav txog qhov khoom siv hluav taws xob.
Unplug 5-inch floppy drive fais fab ntsaws rau hauv rooj plaub. Tig lub hwj chim, xyuas qhov tso zis DC nrog lub tshuab hluav taws xob, ntxiv rau 5V, ntxiv rau 12V yog qhov qub. Tua lub hwj chim thiab ntsaws rau hauv lub hwj chim plug ntawm lub floppy drive, thiab ces tig nws dua, thiab qhov txhaum tseem tsis hloov. Thaum kawg, nyob rau hauv tag nrho cov load, DC tso zis ntxiv 5V yog ntxiv rau 4.1V, thiab ntxiv 2V yog ntxiv rau 10.4V. Cov zis hluav taws xob qis dua ntawm cov khoom siv hluav taws xob cuam tshuam rau kev ua haujlwm ib txwm muaj ntawm lub tshuab floppy drive, uas ua rau tsis nyeem cov disk ib txwm. Tom qab pom qhov ua rau, tshem tawm cov khoom siv hluav taws xob rau kev kho. Thaum lub teeb yog lub teeb, lub zog tso zis yog qhov qub; thaum lub load hnyav, lub zog tso zis txo. Nws qhia tau hais tias lub peev xwm thauj khoom ntawm cov khoom siv hluav taws xob tswj tau txo qis. Qhib lub hau ntawm lub hwj chim lub thawv, thiab siv lub oscilloscope los xyuas kom meej tias lub waveform amplitude ntawm terminals 8 thiab 11 ntawm TL494 tivthaiv thiab lub teeb liab amplifier raj tsis cuam tshuam los ntawm lub load. Thaum lub waveform ntawm qhov ntxiv 5V winding ntawm lub converter raug kuaj pom, lub load yuav cuam tshuam rau nws, tab sis qhov kev hloov pauv me me heev. Yog li, nws xav tias qhov kev poob qis ntawm qhov ntxiv rau 5V rectifier diode yuav loj dua, uas ua rau muaj peev xwm txo qis. Tom qab hloov qhov ntxiv 5V rectifier raj, lub hwj chim ntawm qhov kev sim dua, qhov txhaum tsis tuaj yeem txiav tawm, thiab kev saib xyuas muaj teeb meem nyob rau lub sijhawm no. Tom qab kev tsom xam siab, qhov cuam tshuam rau DC tso zis kuj yog lub hwj chim hloov raj. Tom qab hloov lub hwj chim hloov raj, pib qhov kev sim. Thaum lub load hloov, cov zis DC yog qhov qub, thiab qhov ua txhaum raug tshem tawm. Lub raj fais fab hloov pauv tau sim nrog JL-1, thiab qhov loj me me heev. Tom qab ntawd, kuv tau kawm los ntawm cov neeg siv tias lub tshuab no tau ua haujlwm tsis tu ncua rau ntau tshaj 4 xyoo. Qhov no yog qhov tsis ua hauj lwm ntawm lub hwj chim raj aging. Los ntawm cov ntaub ntawv no, nws tuaj yeem txiav txim siab tias thaum lub microcomputer tsis ua haujlwm, qhov tso zis hluav taws xob ntawm DC fais fab mov yuav tsum tau kuaj ua ntej, uas yog qhov zoo heev rau cov neeg ua haujlwm tu kom nqaim qhov kev ua txhaum thiab tshem tawm qhov txhaum sai.
