Ọ bụ oge ị attentiona ntị na ụfọdụ nkọwa na nchọpụta nke PCB mbadamba, ka ịkwadebe nke ọma iji hụ na ịdị mma ngwaahịa. Mgbe anyị na -achọpụta bọọdụ PCB, anyị kwesịrị ị attentiona ntị na ọgụgụ isi 9 ndị a.

1. Amachibidoro kpam kpam iji akụrụngwa nnwale ala iji kpọtụrụ TV, ọdịyo, vidiyo na akụrụngwa ndị ọzọ dị na efere ala iji chọpụta bọọdụ PCB na -enweghị transformer iche.

Anwalela igwe onyonyo, ọdịyo na vidiyo ozugbo na -enweghị ikewapụ ikewapụ nwere ngwaọrụ nwere ntọala. Ọ bụ ezie na onye na -edekọ ihe n’ozuzu nwere onye ntụgharị ọkụ, mgbe ekpughere ya na ike nrụpụta pụrụ iche ma ọ bụ ibu nke ọdịdị nke ike eletrik amaghị ọtụtụ ihe gbasara TV ma ọ bụ akụrụngwa stereo, buru ụzọ mee ka o doo anya na ebubo chassis igwe, ma ọ bụghị nke ukwuu dị mfe na ndụ ala. Igwe onyonyo, ọdịyo na akụrụngwa akụrụngwa ike ndị ọzọ, gbasaa na sekit agbakwunyere, mmebi ndị ọzọ.

2. Lezienụ anya maka mkpuchi mkpuchi nke igwe nchara ọkụ mgbe ị na -achọpụta bọọdụ PCB

Enweghi ike iji igwe ịgbado ọkụ nwere ike dị ndụ. Iji jide n’aka na igwe ịgbanye ọkụ anaghị adị ndụ, ọ kacha mma ịkwatu shea nke igwe ịgbado ọkụ. MOS circuit kwesịrị ịkpachara anya karịa, ọ dịkwa mma iji igwe sekit obere ọkụ nwere 6-8V.

3. Tupu anyị achọpụta bọọdụ PCB, anyị kwesịrị ịghọta ụkpụrụ ọrụ nke sekit agbakwunyere na sekit metụtara

Tupu ịlele na ịrụzi okirikiri agbakwunyere, anyị kwesịrị ibu ụzọ mara ọrụ nke sekit agbakwunyere, sekit dị n’ime, akụkụ eletriki eletriki, ọrụ nke ntụtụ ọ bụla na voltaji nkịtị, ifegharị ntụtụ na ụkpụrụ ọrụ nke sekit mejupụtara. components. Ọ bụrụ na ọnọdụ ndị a dị, nyocha na inyocha dị mfe.

4, bọọdụ PCB nnwale anaghị ebute sekit dị mkpirikpi n’etiti atụdo

Mgbapụta voltaji ma ọ bụ oscilloscope probe test waveform, mkpịsị akwụkwọ ma ọ bụ nyocha anaghị ebute okirikiri dị mkpirikpi n’etiti eriri sekit agbakwunyere n’ihi mmịfe, ọ kacha mma ka ejikọ ya na ntụtụ nke sekit na -ebi akwụkwọ mpụta maka nha. Sekit ọ bụla dị mkpụmkpụ nwere ike mebie sekit ejikọtara ọnụ ngwa ngwa, yabụ ekwesịrị ịkpachapụ anya mgbe a na -anwale okirikiri agbakwunyere CMOS.

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

Mgbe ị na -atụ voltaji DC nke atụdo nke sekit agbakọtara ọnụ, jiri igwe multimeter nke nguzogide ya karịrị 20K ω /V; ma ọ bụghị ya, a ga -enwe nnukwu njehie nha maka ụfọdụ voltages pin.

6. Lezienụ anya na mkpocha ọkụ nke okirikiri agbakwunyere ike mgbe ị na -achọpụta bọọdụ 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, nchọpụta iduzi PCB kwesịrị ịdị mma

Ọ bụrụ na ọ dị mkpa ịgbakwunye ihe ndị dị n’akụkụ iji dochie akụkụ mebiri emebi n’ime sekit agbakwunyere, ekwesịrị ịhọrọ obere ihe, na wiwi kwesịrị ịbụ ihe ezi uche dị na ya iji zere njikọ parasitic na -enweghị isi, ọkachasị iji mesoo njedebe nke etiti n’etiti ụda olu na -arụ ọrụ. circuit preamplifier.

8. Gbaa mbọ hụ na ịdị mma nke bọọdụ PCB

Mgbe ịgbado ọkụ bụ n’ezie welded, nchịkọta solder na pores dị mfe ịkpata ịgbado ọkụ mebere. Oge ịgbado ọkụ n’ozuzu ya abụghị ihe karịrị sekọnd 3, na ike nchara ahụ bụ ihe dịka 25W. Ejikọla sekit agbakwunyere iji lelee nke ọma, ọ kacha mma iji ohmmeter tụọ ma enwere obere sekit dị n’etiti atụdo ahụ, gosipụtaghị ihe nrapado nchara ma wee gbanye ọkụ.

9, nchọpụta bọọdụ PCB anaghị achọpụta ngwa ngwa mmebi nke sekit agbakwunyere

Do not easily judge that the integrated circuit is damaged. Because the vast majority of integrated circuits are directly coupled, once a circuit is abnormal, it may lead to multiple voltage changes, and these changes are not necessarily caused by the damage of the integrated circuit, and in some cases, the measured pin voltage is consistent with or close to the normal value, it may not be able to show that the integrated circuit is good. Because some soft faults do not cause changes in DC voltage.

PCB board debugging method

Maka bọọdụ PCB ọhụrụ eweghachitere, anyị kwesịrị ibu ụzọ lelee ma enwere nsogbu dị na bọọdụ, dịka ma enwere mgbawa doro anya, ma enwere okirikiri sekit, sekit mepere emepe na ihe ndị ọzọ. If necessary, check that the resistance between the power supply and the ground is large enough.

Maka bọọdụ sekit e mere ọhụrụ, nbinye aka na -ezutekarị ihe isi ike ụfọdụ, ọkachasị mgbe bọọdụ buru ibu, ihe mejupụtara ya, anaghị amakarị etu esi amalite. Mana ọ bụrụ na ị mara usoro nbipu nwere ezi uche, nbipu ga -enweta nsonaazụ ya ugboro abụọ na ọkara mbọ.

PCB board debugging procedure

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, wee tinye akụkụ nrụnye. Modulu nọọrọ onwe ha, ọ bụrụ na ị hụghị na ha na -arụ ọrụ nke ọma, ọ kacha mma ka ị ghara ịwụnye ha niile, mana akụkụ nke nrụnye (maka obere sekit nwere ike itinye ya otu oge), ka ọ dị mfe ikpebi mmejọ ahụ. dị nso, nke mere na mgbe ị zutere nsogbu, ị maghị ka esi amalite.

Generally speaking, you can install the power supply part first, and then check whether the power supply output voltage is normal. Ọ bụrụ na ị maghị oke mgbe ị na -agbanyụ (ọbụlagodi na ị bụ, a na -adụ gị ọdụ ka ị gbakwunye fuuz, naanị ma ọ bụrụ), ị nwere ike ịtụle iji ihe nhazi ọkụ ọkụ na -agbanwe agbanwe nwere ọrụ mmachi ugbu a.

Buru ụzọ debe nchedo ugbu a, mgbe ahụ ọnụ ahịa voltaji nke onye na -ahụ maka ike eletrik ji nwayọ nwayọ, wee nyochaa ntinye ntinye, voltaji ntinye na voltapụta mmepụta. If no overcurrent protection occurs and the output voltage is normal, the power supply is OK. Ma ọ bụghị ya, kwụpụ ọkụ eletrik, chọta mmejọ ya, wee megharịa usoro ndị a dị n’elu ruo mgbe ọkọnọ ọkụ dị mma.

3, wee jiri nwayọ wụnye modulu ndị ọzọ, etinyere modul ọ bụla, ike na nnwale, gbanye ya dịka usoro ndị a dị n’elu, iji zere imebiga ihe ókè wee kpọọ ihe ọkụ ọkụ n’ihi njehie imewe ma ọ bụ njehie nrụnye.

Chọta ngwọta nke bọọdụ PCB na -adịghị mma

1. Tụọ voltaji iji chọta bọọdụ PCB na -adịghị mma

The first thing to confirm is whether the voltage of the chip power pin is normal, and then check whether all kinds of reference voltage is normal, and whether the working voltage of each point is normal. A typical silicon triode, for example, will have a BE junction voltage of around 0.7V and a CE junction voltage of around 0.3V or less. Ọ bụrụ na triode nwere volta njikọta BE karịrị 0.7V (ewezuga maka triodes pụrụ iche dị ka tubụ Darlington), njikọ BE ga -emepe.

2, signal injection method to find the fault PCB board

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. Mgbe ụfọdụ anyị ga -ejikwa ụzọ dị mfe, dị ka ijide tweezer iji metụ ọnụ ntinye aka na ọkwa niile iji hụ ma enwere mmeghachi omume na ọdụ mmepụta, nke a na -ejikarị na sekit ọdịyo na vidiyo (mana ekwesịrị ịmara ya). na enweghị ike iji usoro a na sekit nwere efere dị ọkụ ma ọ bụ sekit dị elu, ma ọ bụghị ya, ọ nwere ike ibute ujo ọkụ). Ọ bụrụ na enweghị mmeghachi omume tupu emetụ aka, na enwere mmeghachi omume mgbe emetụchara aka, ọ na -egosi na nsogbu ahụ dị na ọkwa gara aga, kwesịrị ilekwasị anya na nyocha.

3. Other methods for finding faulty PCB boards

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

“Lee” bụ ịhụ ma enwere mmebi mebere igwe mebere ya, dị ka mgbawa, ịgba ọchịchịrị, nrụrụ, wdg;

“Gee ntị” bụ ige ntị ma ụda ọrụ ọ bụ ihe nkịtị, dị ka ihe ụfọdụ ekwesịghị ịda na mgbanaka, mgbanaka anaghị ada ma ọ bụ ụda adịghị mma;

“Isi” bụ ịlele ma enwere isi, dị ka isi ire ọkụ, ụtọ electrolyte, maka onye na -arụzi elektrọnik nwere ahụ, na -enwe mmetụta nke ọma maka isi ndị a;

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

Ụfọdụ ngwaọrụ ike, mgbe ha na -arụ ọrụ, na -ekpo ọkụ, ọ bụrụ na oyi na -atụ aka, ị nwere ike kpee ikpe na ọ naghị arụ ọrụ. 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. Kedu ihe ogo 70 pụtara? 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).