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A Windows Closing/Opening Power Supply Repaired And Maintained

By on April 20, 2024
power supply Repair







A Windows installing technician brought me this dead power supply for repair. The main job of this power supply to provide power to a motor that controls the opening and closing aluminum windows at homes. He said he has many of them for repair but he brought me a sample to see if it is fixable or not.

repair power supply windows

The customer said this is an expensive power supply and if it works out,

he will provide me with tones of things to fix so that was my biggest motivation for this repair.

windows pcb board repair

Based on what the customer said this board went dead so he opened it and the fuse was open so replaced it with a good one; the fuse was open again when powering on and that gave me an idea where to start.

fixing power supply for windows

I added a fuse and powered it through a current limiter and the light bulb was so bright and stayed bright indicating a short on board.

I checked the bridge rectifier and it was fine. Then next step was… well, check it out.

bad varistor

Could it be that easy? The varistor was cracked open and that is one of the causes found in shorted boards like this.

split varistor

I replaced it with the same brand number for I have plenty of them in the shop and of course I checked parts around in that area and found everything according to specs.

It was time to power it on and see the outcome. I am going to power it though my current limiter and see how it goes.

how to fix and repair abroken power supply for controlling window

I know the photo is not clear but it is obvious that it powered on just fine and the light bulb was bright then it went dim indicating a working board.

I called the customer for pick up and he was happy; he brought more power supplies to be worked on and I was hoping all have the same issue…

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.

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Note: You can check his previous article on Security Camera Does Not Have A Steady Charge Repaired. PT-848




  1. Albert van Bemmelen

    April 20, 2024 at 2:38 pm

    Something is really going bad with the power line voltage at the customer's home, or they use low quality varistors now too? Apparently this German device uses a mainboard that was made in Italy.
    Recently I got 2KV HV parts from China that only tested good upto about 1,5KV! And they were smaller than the usual 2KV components I already had in stock.

    • Waleed Rishmawi

      April 22, 2024 at 1:32 pm

      Albert: it was not at the customer's house, it was at a work place somewhere else. by the way, all the boards he brought for repair all had the same exact issue and all these boards were brought from different locations in different areas. any easy job and an easy income. have a blessed day

  2. Yogesh Panchal

    April 20, 2024 at 3:14 pm

    Good Job! Waleed
    Here confidence to tackle works.....

    • Waleed Rishmawi

      April 22, 2024 at 1:34 pm

      Yogesh: thanks man. confidence come from experience and it is our best tools to fix things. have a blessed day

  3. Parasuraman S

    April 20, 2024 at 11:52 pm

    Good job, dear friend! Thanks for sharing!

    • Waleed Rishmawi

      April 22, 2024 at 1:34 pm

      Parasuraman: thanks dear friend. you are most welcome and have a blessed day

  4. Imoudu.O

    April 22, 2024 at 4:53 am

    More work coming,with more income i guess!!, have a nice day

    • Waleed Rishmawi

      April 22, 2024 at 1:35 pm

      Imoudu: yes more boards to fix and all were having the same exact fault which is an easy repair and easy sweet income. have a blessed day


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