Tuesday, February 23, 2021

LG home theater model HT806 came in dead now repaired

 I got a phone call from one of my neighbor who wanted his home theater checked by a technician.

I passed by his place and took the machine to the shop, he has given me a hint that he suspects the machine was hit by power surge.

Once in the shop I applied power and indeed the machine was dead as dodo.

Tuesday, February 9, 2021

40 Inch Sony Bravia LED television came dead, Red light blinking 6 times, NOW REPAIRED

I got a whatsup message from my former colleague where I used to work but now working with an international organization (Red Cross) I.T department.

The message was, and I quote “My Sony Bravia model KLV-40R352B has a red light blinking 6 times, is it repairable” answer, Yes! Repairable while you wait! Okay, I will bring it tomorrow.

As you have noted I replied with confidence that the problem is repairable, Sony products has state of the art design in the market.

In case of any problem they go into shutdown(lockdown) to avoid further damages, for Sony Led television, the number of blinks point to the faulty circuit. A quick search on google for 6X blinks points to backlight failure.

The following day he brought the television but since I was going out for a meeting we agreed he collect the machine the following day.

The following day I came back to the shop and did not even remember to test if what he said is correct and therefore proceeded to open the television and went straight to the backlight section. You can learn how to access backlight like a pro here.

Tuesday, February 2, 2021

32 inch Skyworth LED television came in with symptoms” Logo comes on briefly” and then go into standby

I got this referral from my FB page, a client who was impressed by the work I share on my Facebook page about my repair work got interested and send a message that she has 32-inch television which need checking by a technician and suspected it was backlights.

From the symptoms she described even me I was convinced that the problem is on the backlight.

I booked her for appointment and send my location ping and the following day I got a phone call from the uber man that he is trying to reach my shop.

I went out and found the uber with a lady passenger at the back seat, with her was a 32-inch television.

The uber driver was released and we proceeded to the shop with the lady.

After reaching the shop the first thing to do is to confirm what the client said is correct and also make sure the screen is still intact.

The screen was okay and the symptoms were also confirmed to be exact.

I opened the television and after doing some board scanning I noted some three small capacitors on the output (actually led driver circuit which had their top silver lining slightly swollen.

Tuesday, December 29, 2020

How microwave oven works

Microwave oven popularly known as a microwave was invented by an American scientist Percy Spencer in 1958 by accident.

The use for microwaves as the preferred mode of cooking/warming food in seconds has become a preferred mode of cooking food by most families.

So how does the microwave work? First let me say that microwaves, unlike other cooking methods like gas and electric coils cook food using frequency.

Thursday, October 15, 2020

21 Inch JCV Television came in dead NOW repaired!

I received a phone call from my neighbor who wanted his television checked by a technician, I passed by his place and picked the television.

 I went back to the shop and after applying power via my series current limiter bulb I noted the Television has no sigh of life.

 But listening carefully I could hear some chi-chi sound coming from I can’t tell exactly where. I opened the television and tested across the man capacitor and I get around 300 vdc which is not bad for those using 240 Vac.

 I tested across all the secondary outputs and I got less near zero volts on all outlets, I decided to switch the power off and do some resistance testing across all the secondary outputs, this was done across the secondary diodes and I noted one line was dead short.

 Upon close investigation I noted it was the B+ line and therefore decided to check the health of the HOT transistor and to my surprise it was dead short.

Monday, September 14, 2020

How a micro switch works

A micro switch, is an electric switch that is activated by very little physical force, of late they have become very popular due to their low cost and high durability.Commonly used in microwaves, rich cookers, blenders etc

Friday, September 11, 2020

Foundations of Electricity & Electronics Course By Humphrey Kimathi

Foundations of Electricity & Electronics Course.

Course code: 14RESFEE 

This course is not about Radio Communications.

This course is intended for those starting out in the world of electricity and electronics.

The course starts at the beginning and takes you through to a solid knowledge of electrical principles. You will then explore the important beginnings of electronics.

This is an assignment based correspondence course via email.

The assignments are in MS Word format.

In total there are 11 assignments. 

You read the course material and complete your assignment then return it via email to your facilitator/trainer. The facilitator will then review your assignment and give you feedback on your work. You can progress at any pace, fast or slow. Your assignment will then be returned to you via email with your next assignment.

 Just some of the topics covered in this source include: -

Atoms – charge -Ohm’s law- basic circuits – series & parallel circuits – inductance – capacitance – reactance - cells and batteries – alternating current - measuring devices - transformers – impedance – RLC circuits – resonance – power supplies -mains power – semiconductor theory – diodes – LED – zener- transistors – and much more.