Don't Miss

An AC control Board Restored Back to Life

By on June 29, 2020
ac control board repair








An AC technician who is a good customer and a dear friend of mine brought this board for repair. As the technician explained the problem I came to understand that the board is working fine but the air compressor is not coming one for some reason.

how to repair air cond board

As you can see, it was all dusty and needed some TLC (tender Loving care) and that is exactly what I did.

I gave it a good clean and then I started looking for the fault on that board.

how to repair ac control board

And as I checked across the board with my naked eye, I saw this fault; One Zener Diode was rusty, and a loose part that I could not figure out why till later.

shorted zener and diode

The Zener diode and the diode were testing ok but because they were rusty, I replaced them and went on to check the part next to them.

blown thermistor

This part was blown to pieces and the number on it was not found. I had to do some checking to find out what that part is.

As I called the technician, he informed me of good news that he has a working board just like that and he was willing to bring it over so I can find out what the part number of this component.

circuit board repair

This is the location of the part on that board. The information found on the opposite side of this board, it gave me some information about this part. I believe it was a thermistor and when the guy brought the working board to my shop, the part was confirmed. It was Thermistor with 102 numbers on it. I could not find the same number but the closest was 104. I soldered on board and gave it to the technician to install it and check it out.

The next morning, the technician called and confirmed all went well and the AC is up and running. He informed me also with good news; he found a used AC unit for cheap price and he is coming today to install it in my shop.

Mission Accomplished.

This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment.

P.S- Do you know of any your friends who would benefit from this content that you are reading now? If so, forward this website to your friends or you can invite your friends to subscribe to my newsletter for free in this Link.

Note: You can check his previous repair articles in the link below:




  1. Albert van Bemmelen

    June 29, 2020 at 9:26 pm

    Hi Waleed, everything was clear until the last sentence of your article where you wrote:

    "He informed me also with good news; he found a used AC unit for cheap price and he is coming today to install it in my shop" ?

    Why is that good news to you? And why does it need to be installed? Thanks if you can clearify this.

    • Waleed Rishmawi

      June 29, 2020 at 10:25 pm

      Albert: I do not have an air conditioning in my shop and I was looking for cheap one that does the job and on that day he found one and installed it to. Have a blessed days.

      • Waleed Rishmawi

        June 29, 2020 at 10:34 pm

        Albert: it is a two pieces ac unit. They had to make a whole in the wall To install the two units together. Good news for me because I needed one in the shop and these units are expensive but found a cheap but good one .

        • Albert van Bemmelen

          June 30, 2020 at 1:09 pm

          Understood, but know that although you maybe got your airconditioning cheap it probably needs new air cooling refrigerants R-134a to R-1234yf (or whatever they now allow to be used in cars and homes because they can contaminate/influence the global warming environment) about every 8 to 10 years because the pipes leak the refridgerant in time and need to be refilled under pressure. My brother has 2 installed in his home and one needed refilling after about 8 years because it stopped working without enough pressured refridgerant in the system.
          Because of heavy regulations only special firms are allowed to refill those air condition systems in my country but apparently they sell it in countries like Dubai in the supermarket for every customer like bread and butter.

          • Waleed Rishmawi

            June 30, 2020 at 6:56 pm

            Albert: no I do not need that. It is already up and running.

          • Waleed Rishmawi

            July 1, 2020 at 3:10 pm

            Albert: the term cheap does not mean bad quality or needs cooling means someone bought a new ac and wanted to sell the old one. the AC unit came in an excellent conditions, has the cooling refrigerants and needed only installation. once it was done, I was enjoying the coolness of it in my shop. have a blessed day

  2. Parasuraman S

    June 30, 2020 at 6:43 am

    some TLC (tender Loving care) - Well, that explains your mindset and heart you have to solve any problems! Well done!

    But like Albert van Bemmelen, I too wonder what do you mean by 'he is coming today to install it in my shop' Probably it is a typing mistake and it could be 'deliver to my shop'! Am I correct?

    • Waleed Rishmawi

      June 30, 2020 at 12:33 pm

      Parasuraman: the customer is an AC technician so brought the unit and he installed it in my shop. It is not a mistake he actually came and installed it in my shop.

  3. Greenford William Mafuleka

    June 30, 2020 at 2:54 pm

    Hallow Waleed,
    Great repair jobs all the time. I wished, I was your assistant work assistant.

    • Waleed Rishmawi

      June 30, 2020 at 7:19 pm

      Greenford: thanks man. have a blessed day

  4. Mark

    June 30, 2020 at 7:54 pm

    Hey Waleed,
    Well done on your repair.
    Was this hit by a lightning strike? It's not unusual to see a thermistor get blown apart during a lightning strike.

    • Waleed Rishmawi

      July 1, 2020 at 3:06 pm

      Mark: no it was not hit by a lightning strike. it just got old and need to be replaced and maintained.

  5. Gassan Ali

    July 1, 2020 at 2:55 am

    Nice work! Your term "TLC" put a big smile on my face.It made me stop and ponder. I used to watch wrestling as a kid and one of the most brutal matches were called TLC matches. It stands for "Tables, Ladders and Chairs". The contestants can use these objects as weapons. Your TLC means the total opposite of that. Tender Loving Care! Cheers. Have a nice day!

    • Waleed Rishmawi

      July 1, 2020 at 3:07 pm

      Gassan: thanks man. have a blessed day

  6. Joven Urbano

    July 3, 2020 at 1:59 am

    Well done! You were fortunate to have a working board as a reference for that unidentifiable part. Is it a thermistor or a thermal fuse. If it is a thermal fuse, the number 102 could be the temperature beyond which it will blow off. If such is the case, replacing it with 104 won't matter much. Thanks for sharing!

  7. saunders

    July 7, 2020 at 10:49 pm

    Is there a way to fix this e6 error problem on my ymgi minisplit indoor unit without buying a new board? I have check the wires they are giving good continuity , I am attempting to repair the board myself without buying it, I watched the videos attached with the problem but most people just replace the board. The unit comes on displays 77 degrees then E6 code show up I am an electronic technician, what part or parts would you think will be most probable to cause the E6 error code.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Free Report