Author Topic: How to test dead components on a board?  (Read 5015 times)

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Online MechatrommerTopic starter

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How to test dead components on a board?
« on: April 15, 2010, 04:32:11 pm »
Can anyone teach a proper way of testing a working or broken components without separating it from its board?

a) Resistor
b) Capacitor
c) Inductor
d) Diode
e) Transistor
f) FET/MOSFET?
g) chips

And Dave, can u make a video on many types of diode and/or transistor and/or FET/MOSFET. Diode alone have many types (Scmith, Schotky, i dont know the names and differences), all i know diode is a one way ticket for the current to flow.
Nature: Evolution and the Illusion of Randomness (Stephen L. Talbott): Its now indisputable that... organisms “expertise” contextualizes its genome, and its nonsense to say that these powers are under the control of the genome being contextualized - Barbara McClintock
 

Offline dds

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Re: How to test dead components on a board?
« Reply #1 on: April 15, 2010, 05:27:44 pm »
Oscilloscope, Huntron tracker, (component tester) while DUT is turned off.
 

Offline dds

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Re: How to test dead components on a board?
« Reply #2 on: April 15, 2010, 05:28:20 pm »
ESR meter for elco capacitors.
 

Online djsb

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Re: How to test dead components on a board?
« Reply #3 on: April 16, 2010, 09:43:16 am »
Hi,
Circuits should be checked using a top down approach wherever possible working from the front panel of a unit and finally down to component level. This helps to isolate a fault to a specific subsystem.
1/ Visual check for burnt components,leaking capacitors,loose components,shorted tracks etc.
2/ Voltage checks using Schematic or service manual if available.
3/ Signals can be injected and traced to narrow down a fault.
4/ When the specific suspect area is isolated then individual component checks can be done.
5/ Most checks can be done with a multimeter using the ohm meter,continuity tester and diode test feature.

a/ Resistor-Check for correct value, open or short circuit
b/ Capacitor-Check if the capacitor charges using the ohm meter.
c/ Inductor-Check for open circuit.
d/ Diode-use diode check for correct forward voltage drop (0.7 for Silicon or 0.3 for Germanium etc) and infinite reverse resistance.
e/ Transistor-Use diode check to test individual PN junctions.
f/  FET/Mosfet-Check drain source resistance.
g/ Chips-Check voltage at power pins and refer to schematic/data sheet for other voltages.

That's the fault finding method I use anyway.
Practice and persistence also helps.
HTH

David.
« Last Edit: April 20, 2010, 08:29:06 am by djsb »
David
Hertfordshire,UK
University Electronics Technician, London PIC,CCS C,Arduino,Kicad, Altium Designer,LPKF S103,S62 Operator, Electronics instructor. Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime. Credited Kicad French to English translator.
 

Offline Kiriakos-GR

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Re: How to test dead components on a board?
« Reply #4 on: April 24, 2010, 05:08:40 pm »
I believe that all the "Ideas" , that David added so far , are all that you will ever need.

But as Mediterranean technician , I would add and the most famous one .. the hammer  ;D ;D ;D

If everything else fails , its your only option  !!  :D

 
 


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