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Domestic A/C Stabilizer Repaired

By on January 2, 2024
ac stabilizer repair







This stabilize was brought to me with complaints of, when plug into ac socket, a loud bang was heard with spark. On diagnosing it, I found cord had strayed, fuse opened, leds pins rusted, variable resistors rusted, switches bad, track to NO of fifth relay from left burnt, voltage indicator defective.

ac stabilizer fix

So I replaced all defective components ,and repaired the damaged track, however I was very careful about replacing those indicator leds. Why? We all know present day manufacturers do all things possible against ‘repair of their products’.

So I have discovered in some domestic AVR’s leds board circuit marking : (+)(-) is deliberately marked wrongly and this one on repair is not an exception, that is cathode is marked with sign +,  while anode is marked with — , and this was done on yellow led only while other three are correct.

led indicator

led wrong polarity

If someone follows marking on led number two(yellow) to fix replacement ,one might end up not being able to repair such device, for that single mistake will affect the operation of device. I have fallen a victim before. Well, this time around I got them(manufacturer) in the wit!.

So having done all things aright and tested device, it worked perfectly and customer was happy. This is the finished repaired work.

how to fix a broken ac stabilizer

checking relay

ac stabilizer repair


imoudu onwuwah

This article was prepared for you by Imoudu Onwumah from Nigeria. He is 62 years old and has just 3 years experience in electronics repairs. I started career in hotel industry as a chef, but then I was doing repairs only in electrical repairs as a hobbyist. In 2018, I decided to learn about electronics which through Jestine’s electronics e-books and holding my hand, am an electronics techie today.

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Note: You can read his previous article on BackLight Problem In LED TV Repaired




  1. Ron McCann

    January 2, 2024 at 9:42 pm

    Thank You for this post. The knowledge that manufacturers actively mislead to make a buck is sinful. keep up the great work and keep posting!

  2. Parasuraman S

    January 3, 2024 at 12:20 am

    Yes, you are very correct! I have seen such deliberate misguidance in many sets. Unless we are aware and careful about such deceits, we will end up burning our fingers! Many thanks for sharing!

  3. Albert van Bemmelen

    January 3, 2024 at 12:43 am

    Good job. It is really amazing how leds have evolved in performance and quality of light and the so many colors. Even the new UV leds and Flash light leds are astounishing. Many new devices wouldn't even be possible today without the modern existing high bright super low current leds. Different coloured leds have different operating voltages with matching serie resistor to limit the max current. With a forward voltage of only 1.5V for IR leds it is the lowest, Red/Orange is about 2V, followed by Green with about 2.2V upto Blue/White being about 3.2V, Purple being about 3 to 3.6V ending with energetic UV leds being as high as 5 to 6V. At best if possible we replace the same led colors as originally were used.

  4. Waleed Rishmawi

    January 3, 2024 at 9:00 pm

    good job on the repair and thanks for sharing. have a blessed day

  5. Chuba

    January 4, 2024 at 8:36 am

    Congrats on the repairs, wonderful article

  6. Yogesh Panhchal

    January 5, 2024 at 8:47 pm

    Good repair,
    Have you brought led PCB From the market? i know some manufacturer who are making PCB for school / College students for learning & troubleshooting . intentionally they print this type of marking so that students learn to trace the circuit & fault finding.In fact for misguiding some manufacturers are putting dummy components by which does not have any Link / connection on the PCB .

  7. Imoudu.O

    January 6, 2024 at 4:19 am

    Thanks for your comments, infact i don't know those colour leds use different operating voltages and i
    have replaced red with yellow led in the past.Now i have gain invaluable knowledge from you, i appreciate it and thanks for sharing.

  8. Imoudu.O

    January 6, 2024 at 4:24 am

    My dear, the system of this present world is evil and this is why all these dishonest acts are going on.Thanks for ur comments

  9. Imoudu.O

    January 6, 2024 at 4:48 am

    If the pcb is produced for learning at schools it's ok, but for homes and offices it's unethical.Thanks

  10. Imoudu.O

    January 6, 2024 at 4:50 am

    Thanks for your comments


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