Saiki wayahe mbayar manungsa waé kanggo sawetara rincian ing deteksi Papan PCB, supaya luwih siyap kanggo njamin kualitas produk. Nalika ndeteksi papan PCB, kita kudu nggatekake 9 akal sehat ing ngisor iki.

1. Dilarang nggunakake peralatan uji dhasar kanggo ngubungi TV langsung, audio, video lan peralatan liyane ing piring ngisor kanggo ndeteksi papan PCB tanpa trafo isolasi.

Aja nyoba langsung piranti TV, audio, lan video kanthi langsung tanpa trafo isolasi daya nganggo piranti grounded. Sanajan umume perekam duweni trafo, yen kena daya output khusus utawa luwih gedhe saka sifat pasokan listrik ora ngerti babagan TV utawa peralatan stereo, luwih dhisik jelas sasis mesin wis diisi, yen gampang banget lan urip langsung ing lantai TV, audio lan sirkuit sumber daya peralatan liyane, nyebar menyang sirkuit terintegrasi, gangguan luwih lanjut.

2. Priksa kinerja jampel saka wesi solder listrik nalika ndeteksi papan PCB

Dilarang nggunakake wesi solder kanthi daya urip. Kanggo mesthekake manawa wesi solder kasebut ora nyata, luwih becik nemplek cangkang wesi solder kasebut. Sirkuit MOS kudu luwih ati-ati, lan luwih aman nggunakake sirkuit voltase kurang kanthi 6-8V.

3. Sadurunge ndeteksi papan PCB, kita kudu ngerti prinsip kerja sirkuit integral lan sirkuit sing gegandhengan

Sadurunge mriksa lan ndandani sirkuit integral, luwih dhisik kudu ngerti fungsi sirkuit integral, sirkuit internal, paramèter listrik utama, peran saben pin lan voltase normal, bentuk gelombang pin lan prinsip kerja sirkuit sing kasusun saka periferal komponen Yen kahanan kasebut saiki, analisis lan inspeksi bakal luwih gampang.

4, papan PCB tes ora nyebabake sirkuit cekak ing antarane pin

Pengukuran voltase utawa bentuk gelombang tes probe osiloskop, pulpen utawa probe ora nyebabake sirkuit cendhak ing antarane pin sirkuit terintegrasi amarga geser, luwih becik langsung disambungake karo pin sirkuit percetakan periferal kanggo ngukur. Sirkuit cendhak cepet bisa ngrusak sirkuit INTEGRAT, mula kudu luwih ati-ati nalika nyoba sirkuit integral CMOS sing dikemas rata.

5, detection PCB board test instrument internal resistance should be large

Nalika ngukur voltase DC saka pin sirkuit terintegrasi, gunakake multimeter sing resistensi internal luwih saka 20K ω / V; yen ora, bakal ana kasalahan pangukuran sing gedhe kanggo sawetara voltase pin.

6. Pay manungsa waé kanggo disipasi panas sirkuit integrasi listrik nalika ndeteksi papan PCB

Power integrated circuits should have good heat dissipation and should not be allowed to work in a high power state without heat sink.

7, Deteksi timbal papan PCB mesthine wajar

Yen perlu nambah komponen periferal kanggo ngganti bagean sing rusak ing sirkuit terintegrasi, komponen cilik kudu dipilih, lan kabel kudu cukup kanggo ngindhari kopling parasit sing ora perlu, utamane kanggo ngatasi pungkasan ing antarane sirkuit audio amplifier sirkuit preamplifier.

8. Mesthekake kualitas las papan PCB

Nalika welding wis gandheng tenan, akumulasi solder lan pori-pori gampang nyebabake welding virtual. Wektu pengelasan umume ora luwih saka 3 detik, lan kekuatan zat besi solder udakara 25W. Sirkuit terintegrasi wis dipasang kanggo mriksa kanthi tliti, luwih becik nggunakake ohmmeter kanggo ngukur manawa ana sirkuit cendhak ing antarane pin, konfirmasi ora ana fenomena adhesi solder banjur uripake catu daya.

9, deteksi papan PCB ora gampang nemtokake karusakan sirkuit integral

Do not easily judge that the integrated circuit is damaged. Amarga mayoritas sirkuit integral ditambah langsung, sawise sirkuit ora normal, bisa uga ana pirang-pirang perubahan voltase, lan pangowahan kasebut ora mesthi disebabake kerusakan sirkuit integral, lan ing sawetara kasus, voltase pin sing diukur yaiku salaras karo utawa cedhak karo nilai normal, bisa uga ora bisa nuduhake manawa sirkuit integral apik. Amarga sawetara kesalahan alus ora nyebabake perubahan voltase DC.

PCB board debugging method

Kanggo papan PCB anyar sing diwiwiti, luwih dhisik kudu dielingi manawa ana masalah ing papan kasebut, kayata ana retakan sing jelas, apa ana sirkuit cendhak, sirkuit mbukak lan fénoména liyane. If necessary, check that the resistance between the power supply and the ground is large enough.

Kanggo papan sirkuit sing mentas dirancang, debugging asring ngalami sawetara kangelan, luwih-luwih yen papane luwih gedhe, luwih akeh komponen, asring ora ngerti carane miwiti. Nanging yen sampeyan nguwasani metode debugging sing cukup, debugging bakal entuk asil kaping pindho kanthi setengah gaweyan.

Prosedur debugging papan PCB

1. For the new PCB board just brought back, we should first roughly observe whether there are problems on the board, such as whether there are obvious cracks, whether there are short circuits, open circuits and other phenomena. If necessary, check that the resistance between the power supply and the ground is large enough.

2, banjur komponen instalasi. Modul independen, yen sampeyan ora yakin manawa bisa mlaku kanthi bener, luwih becik ora nginstal kabeh, nanging bagean saka instalasi (kanggo sirkuit cilik, bisa diinstal kabeh sekaligus), supaya gampang nemtokake kesalahane sawetara, supaya nalika sampeyan nemoni masalah, aja ngerti carane miwiti.

Generally speaking, you can install the power supply part first, and then check whether the power supply output voltage is normal. Yen sampeyan ora yakin nalika aktif (sanajan sampeyan wis disaranake nambah sekring, manawa sampeyan bisa nggunakake regulator voltase sing bisa disetel kanthi fungsi watesan saiki.

Pisanan priksa proteksi saiki, banjur nilai voltase suplai daya regulator alon-alon, lan ngawasi arus input, voltase input lan voltase output. If no overcurrent protection occurs and the output voltage is normal, the power supply is OK. Yen ora, copot catu daya, temokake kesalahan, lan baleni langkah-langkah ing ndhuwur nganti pasokan listrik normal.

3, banjur instal modul liyane kanthi bertahap, saben modul sing diinstal, tes daya, daya miturut langkah-langkah ing ndhuwur, supaya ora kakehan arus lan ngobong komponen amarga ana kesalahan desain utawa kesalahan instalasi.

Temokake solusi papan PCB sing salah

1. Ukur voltase kanggo nemokake papan PCB sing salah

Babagan sing pisanan dikonfirmasi yaiku apa voltase pin power chip iku normal, banjur priksa manawa kabeh jinis voltase referensi normal, lan apa voltase kerja saben titik normal. Triode silikon khas, kayata, bakal duwe voltase persimpangan BE udakara 0.7V lan voltase persimpangan CE udakara 0.3V utawa kurang. Yen triode duwe voltase persimpangan BE luwih saka 0.7V (kajaba triode khusus kayata tabung Darlington), persimpangan BE bisa BE mbukak.

2, metode injeksi sinyal kanggo nemokake papan PCB sing salah

Add the signal source to the input end, and then measure the waveform of each point in turn to see whether it is normal to find the fault point. Kadhangkala, kita uga bakal nggunakake cara sing luwih gampang, kayata nyekel tweezer kanggo tutul terminal input ing kabeh level kanggo ndeleng apa ana reaksi ing terminal output, sing asring digunakake ing sirkuit audio lan video amplifier (nanging kudu dicathet manawa metode iki ora bisa digunakake ing sirkuit kanthi piring basa panas utawa sirkuit tegangan tinggi, yen ora bisa nyebabake kejut listrik). Yen ora ana reaksi sadurunge tutul, lan ana reaksi sawise tutul, nuduhake manawa masalah ana ing level sadurunge, kudu fokus ing inspeksi.

3. Cara liya kanggo nemokake papan PCB sing salah

There are many other ways to find trouble spots, such as seeing, hearing, smelling, and touching.

“Deleng” yaiku kanggo ndeleng manawa ana kerusakan mekanik sing nyata ing komponen, kayata pecah, ireng, deformasi, lsp;

“Rungokake” yaiku ngrungokake apa swarane kerja iku normal, kayata sawetara perkara sing ora muni ing dering, dering ora muni utawa swarane ora normal;

“Mambu” kanggo mriksa manawa ana mambu, kayata mambu kobong, rasa elektrolit kapasitor, kanggo personel perawatan elektronik sing berpengalaman, sensitif banget karo bau kasebut;

“Touch” is to use the hand to test whether the temperature of the device is normal, such as too hot, or too cold.

Sawetara piranti listrik, nalika digunakake, panas, yen adhem wis adhem, umume sampeyan bisa nemtokake manawa ora bisa digunakake. But if it’s hot where it shouldn’t be or too hot where it should be, that’s no good. General power triode, voltage regulator chip, etc., working in 70 degrees is completely no problem. Apa tegese 70 derajat? If you can hold your hand on it for more than three seconds, the temperature is probably below 70 degrees (be careful not to burn your hand).