Dear repair friends,
Once again i am coming back to you to introduce the term ESR (Equivalent series resistance)
Looking above statement many questions in mind
1) Why do we need this ESR??
2) And again why it is so important for Repair /Trouble shoot work?
3) What is the instruments used to find ESR?
Generally there is a term"The rate of failure is proportional to Number of electrolytic Capacitors present in an Electronic equipment"
Yes, Based on my experiences 70% of electronic equipment failure due to capacitors. Then How to find defective caps?
Methods
1)Using Analog Multimeter:-There was the day the method taught my father by using Analogue multimeter the pointer needle that goes to end & coming back to zero for good capacitors but this is not 100% correct.Because i failed to trouble shoot defective caps in many equipment.
2)Using Capacitor Meters:-With the
introduction of expencive Capacitence meter i felt very happy so that this
capacitor meter is the best Detective meter for electrolytic capacitor, Even
this meter also not 100% correct. I failed to trouble shoots even in this
method
3) Physical appeariance:-Mostly capacitors Bulges on defective it is
Easy to identify. Some of the capacitors dry’s an electrolyte
& increases their internal resistance without any physical changes. This
kind of electrolyte is very difficult to identify even a capacitance meter
measures correct but it fails to identify its internal ESR value.
Most of the technicians based on their expierance replaces
the caps if they get doubt while trouble shooting because of its cheap cost.
Then how to identify exactly faulty caps in an electronic circuit?? The answer
is ESR meter
Yes, this meter is my favourite meter i
will call this meter as capacitor police because within a fraction of
minute it can catch the culprit.
3) Physical appeariance:-Mostly capacitors Bulges on defective it is Easy to identify. Some of the capacitors dry’s an electrolyte & increases their internal resistance without any physical changes. This kind of electrolyte is very difficult to identify even a capacitance meter measures correct but it fails to identify its internal ESR value.
Good & Defective capacitor samples
In above pic one is defective
& another is good but no any physical change in appearance
After testing with ESR we
can easily locate the faulty capacitor.
Pls go through below one of my Repair case History to understand the
effectiveness of this Instruments.
The first Repair success story with this
instrument
We received a compliant from Onida crt TV for
repair
After opening the chassis found dual SMPS in
this model
1) SMPS 1 used for driving Audio section &
micro-controller standby
2) SMPS 2 used to power up the rest of the sections through
relay driving
As on trouble shooting i did not found 300V
DC in main filter capacitor @ SMPS 2 back word trouble shooted
Relay is not activated checked the relay
circuit found ok.
Now found relay driving voltage abnormal
coming via micro-controller now suspected on VCC line on micro
Found abnormal showing 5.5Volts DC instead
of 8v DC the culprit is 8V filter capacitor 100mfd/25Volts.
When i checked with above ESR it is shown open.
All this activity taken only 5 to 6 Minutes
Once again thanks to this great instrument
I almost saved 90% of my repair time.
TV pcb with Culprit innocent Capacitor
marked
Then ESR Meter how it looks? pls go through
below ESR Models which is very important ,Every Repair Technician Must
have this instrument to save his precious time.
Blue
ESR
Meter
Common ESR
Meter
Analogue
ESR Meter
Pls go through there details
through Google internet for there operations & Specifications .Depending up
on your Budget one can choose the instrument.
In an up coming article i will let you know its principle of operation
& how to use ESR effectively in trouble shooting work
That’s the end of this article see you in the next
Topic.
With Best Regards
Pls go through below one of my Repair case History to understand the effectiveness of this Instruments.
