Test integrated circuit HOW TO TEST ICs CHIPS by Multimeter

HOW   TO  TEST   ICs    CHIPS     by     Multimeter  

ICs   is  a    circuit and  there are  many small  electronic components  inside it.   ICs has many type , style ,  including its complexity.    On   this article  I will refer to standard  ICs   that  we always find it   at common circuit and I will use standard ICs  for example testing.    For special purpose ICs you can check  with  ICs  maker  how to check and test  it  ,  test guide and specification data can  get these from datasheet ;   type ICs part number on google  search  by   this  you will find datasheet as PDF file.  On datasheet  will  present electrical characteristic  , test graph for designer  and  checking , pin  arrangement  function , sizing  for installation   and   safety  advice.

They    are   2  basic method  to check   ICs.
1)  On circuit  testing .    If  you have oscilloscope  and know  how  circuit is working   such as input , output ,condition  to  on  and off , type of  signal  ; then you can consider it  as block diagram  and section to test.
At the ICs you will check  input  voltage  is present  or  not , output occur  after the input switch on/off or not.     Including   Vcc  of  ICs  should be value  as   its rated voltage.

2.    VCC   and   ground   terminal   resistance   checking.    As    inside  the  ICs  there is  some circuit  , it need voltage to supply and the circuit inside must not  " short circuit "  and  " open circuit"  these is the basic condition for good ICs , we will apply this to check ICs   and   describe below.

Take  ICs part number  that   marked on its body to find  pinning function  on datasheet ,  find  where  is VCC and ground pin  locate. Some ICs has many VCC and ground pin ,   you  to check  all  VCC  pinning  and  it  must be good condition for all VCC.     I will use ICs part number HD74LS00P  for example testing.   Set  multimeter  to resistor  test function then   connect   as  shown  on   photo , measure ,   and  read  resistance value.

HD74LS00P  pining arrangement   ( different  ICs  part number  has different VCC pin  allocation )
The notch  and circle on ICs   mean  pin no.  1  start  from that point.

Pin no.  1  start   at  the dot and notch.
                                  TEST ICs CHIPS with Multimeter

                VCC and GND testing , The  first  measurement   and   test   leads    connection

electronic  components  testing
The    first   measured  resistance value is  high ( for good ICs)

VCC and GND testing , the  second  measurement  and  test leads   connection.

The  second  measured resistance value  is  lower  compare to  the first. ( for good ICs)
               TEST ICs CHIPS Multimeter

Good  ICs .... measured  resistance value of  VCC and ground  testing ,  the first measurement  and  second measurement  , the first testing resistance value  is high and the second is low ( compare to the first ).  See  above  photo for   example.

Bad  ICs (leak)........both measured resistance  value   tend to the same value and very  high  resistance.

Bad  ICs (Short circuit) ....both  measured resistance value tend  to  very low resistance ( almost be  0  ohm )

Bad  ICs ( open  circuit) ... the display show  " OL"   for both    measurement.

How   to   check  electronic  device

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