I received a phone call from a client who wanted his television checked.
I arrived at the site and
shown the television, looking at the screen one can see the pictures but pink
color was too much and also the image was not sharp, any writing on the screen
was not visible and looked like washed out.
I took the television to the shop and the first stop was the small CRT neck board shown below.
Noted a lot of dry joints and did re-soldering and when happy I decided to retest the television again to see if the issue has been sorted out.
I re assembled the
television and upon applying the power I noted it was like I had done nothing, no
change at all.
I decided to do some
scanning with my naked eyes and I was not happy with this capacitor C564(1000uF/25V)
though I could not relate this capacitor with the color problem but since it
seems not okay I had to change it and again see if there is any improvement.
I changed the capacitor and after applying the power and checked the impact of that on the screen I noted still no change.
In electronics there is no
guess work, even if you change all the components on the board and miss the culprit
the machine will behave as though you have not changed anything.
Same to medical, if the
doctor mis-diagnose your problem and give all the medicine in this world, you
will have no improvement until you get the correct diagnosis.
With this second attempt and
no improvement I decided to up my game.
In electronics we usually
troubleshoot from known to unknown.
Since all the known has not
worked, I have to pull my ESR meter to do ESR test on all capacitors around
By the way most of equipment
referred to me from other technician as un repairable always end up with a
faulty capacitor and since where I come from technicians find it too expensive
to invest in an ESR meter they end up replacing the whole board and if the
owner is able to pay the huge bill which include the new board plus the tech
profits most customers decide to pick their items and that’s how I get some
Once a customer gets to know
that the item which was condemned to dustbin has been restored to life they
trust me with all their electronic gadgets and refer more customers along the
Anyway that is not what brought
me here today, let us continue with our troubleshooting.
While doing ESR in circuit test
I noted one capacitor which the meter read open (high), I turned the board the
other side and noted the capacitor is rated 10uF/250V(C592).
Looking at the working voltage
of this capacitor I could tell it is used to filter the high RGB amplifier
voltage usually around 180 volts’ dc and this could be the culprit since any
issue with that line can cause all manner of problem to that small CRT neck board.
While out of circuit I decided to test using my multi-components tester and the results still showed Positive as you can see below.
The ESR reading is 0.15KΩ x
1000=150Ω, for those who know an ESR of more than 5 Ohms can bring down a jet
fighter. What about 150 ohms? Maybe can sink a whole ship.
I decided to replace this
capacitor with another one from a junk and see if I had got it right this time
and this is what I saw.
The television is happy and
the singer is also happy.
Thank you guys.