Monday, January 13, 2020

43 inch Samsung plasma television (model PS43F4500) dead, red led blinking 3 times now repaired.


A client contacted me via my Facebook ad with an issue of faulty Samsung television.

Since the advert was broadcasted in the city of Nairobi, I expected him to be from within the city but it turned out he was from quite far place from where my workshop is.

I pointed to him my willingness to repair his television but distance does not favor us.

He promised to bring the machine up to my shop when coming to Nairobi and I left it at that.

Monday, December 30, 2019

Do it yourself isolation transformer

As a technician you have come across many transformers, First on the list is step down transformer which work is basically to step down voltages like 110Ac to 12Vac or 240Vac to 12Vac etc.

We also have step up transformer which steps up the voltage, a good example is fly-back transformer.

Another transformer available in the market is isolation transformer (this transformer has the ratio 1:1) which means if you give it 110Vac on the primary you will get 110Vac on the secondary side. Give it 240Vac on the primary and you get 240Vac on the secondary side.

So what is the purpose of using this transformer and get the same voltage (results)

This is where isolation (separation) comes in. this means even if the secondary voltage is still the same, it is not connected directly to the main supply but done in isolation (magnetically) so to speak.

Monday, November 25, 2019

Sony Bravia model KDL-32R300B came in dead “red led blinks 6 times” now repaired.


This television came from a friend with the complaints above, I tested it at his place and I confirmed the symptoms.

So I took it with me to the workshop and since I confirmed the symptoms at the owners place I went straight to open the panel and accessed the backlight and after testing with my backlight tester I did not get any fault led and I was frustrated because I expected it to be easy fix.


Monday, November 18, 2019

LCD LED Television training seminar at Airport Gate view hotel Utawala-Kenya


Calling on all LCD LED television repair technician

        Back-light repair seminar

On Saturday 13th December 2019 Hum-tech electronics is going to hold a training seminar at Airport Gate view hotel Utawala.

Time: 10.00 am – 3.00 pm

Participation fees- $30 USA dollars (3000 Kshs)

What you will learn

  • Introduction to LCD-LED television


  • Understanding LCD-LED television backlight(LED/CCFL)


  • How to access LED backlight like a professional without breaking the screen.


  • How to change LED television backlight strip or individual LED.


  • How to order and buy spares parts online safely.


  • How to advertise your business using Facebook.


  • Seminar include theory and practical’s


  • Free snacks



The class will compose of only 10 participants, the eleventh student will be booked in the next class.



BOOKING:whatsup  +254 733 475 040  



Facilitator: Humphrey Kimathi

Wednesday, November 13, 2019

LCD/LED TELEVISION REPAIR CASE HISTORY VOL.1

Introducing my latest eBook on LCD/LED television repair case history vol.1

Click on the book cover below to have it on your workbench.

Thursday, October 17, 2019

Sanyo 21 inch CRT television model CM21MS22, No audio, messed up color, and visible white lines across the top part of the screen now repaired.


I received a call from a customer who wanted her television checked by a technician.The complaint was the television had picture but no audio.

Upon reaching her home I decided to power on the television to confirm the symptoms and this is what I saw.


Monday, September 9, 2019

JIEPAK 19 inch Led television dead now repaired


A customer brought in 19 inch Led television for check up, complaint was the television was not able to power up.

It was attempting then shut down in cycles, since it was using power adapter I tested the output from the adapter power supply and I got 12.44 vdc.
This looks okay according to the printed output on the adapter body.

So now I was ready to go the next level, opening the television and do further troubleshooting.

But before that I decided to swap the power adapter with the one I use in the shop for testing television in case the owner forgot to bring it along.

After powering the television I was surprised to see the TV has picked up and now working perfectly.
With this I concluded the problem was on the power adapter, but did I not get 12.44 Vdc?