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Treadmill Repair

By on June 29, 2013
treadmill repairing

A dead treadmill that brought back to life

A guy who is selling second hand sport equipment brought a power board that was dead. This power board is a part of a treadmill machine. He could not bring the whole machine because it is too heavy to carry it and my shop is too small to receive such a machine.

treadmill repair

The moment I took a look at this board, I could see that the main fuse was open and I noticed that because the fuse was really dark on the inside indicating a serious short on that board. I connected a 100 watt light bulb to the main fuse connectors and powered up the machine and to my surprise, the light bulb went dim indicating that the board is ok and there is no short in it. I was really surprised to see that. I could test 300 DC volts on the motor negative and positive connectors indicating a working power board.

For your information, I never worked on such boards so I had to ask a friend of mine about it because he repairs such equipment. When I asked him, he smiled and said, yes my friend, the motor connector is giving you 300 DC volts that is a good sign but the motor that should be connected to this socket is not in good working condition. That is why the fuse was open and he pointed to a transistor G30N60 which is actually a MOS N FET and said this transistor is shorted as well. I checked it out with a multi meter and it was actually shorted. When I replaced this transistor and put a motor that he had in his shop, the motor started to spin nicely. 

treadmill troubleshooting

I called the customer and told him that the board is ready but gave him a warning about the motor that he have. It should be fixed first before adding this power board to it otherwise the fuse will be shorted and the transistor will blow again. He accepted this idea and sent the motor to be fixed. He gave me a call later that day that the motor was actually bad and now it was fixed.

He came and took the board and installed it in the treadmill and it worked nicely.

It was a new experience to me and was very happy that all went well.

waleed rishmawi




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. Please give a support by clicking  on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

By the way if you have any good repair article that you want me to publish in this blog please do contact me HERE.



  1. shihab kably

    June 29, 2013 at 5:07 pm

    This article shows the importance of cooperation between repairers.

    • Jestine Yong

      June 29, 2013 at 11:49 pm

      HI Shihab,

      If you have any good repair articles you too can contribute to this blog. The more people share the more we know about different types of repair.


      • Miguel

        June 6, 2020 at 9:48 am

        Just started following this articles and I am very into it. Like to try and fix things and add to my knowledge. I have the same issue with a similar power board, same component shorted. What should I check on the motor before reconect all back.

    • Waleed Rishmawi

      June 30, 2013 at 11:47 pm

      very true Shihab. we as techicians here in Bethlehem area always ecourage and help each other. I find that really great.

  2. beh

    June 29, 2013 at 6:00 pm

    principals of all psu smps are the same in all electronic machines and we should not scare from them we have to open the power supplies and take look may be we find a culprit components as you did. congratulations for your courage and yes you made it.

    • Jestine Yong

      June 29, 2013 at 11:50 pm

      Hi Beh,

      Yes since we already have knowledge in electronics repair there is no harm in trying. Never try never know. And Waleed have tried it and successful.


      • Waleed Rishmawi

        June 30, 2013 at 11:50 pm

        Thanks Jestine for giving me the chance to share my experience. it is a joy to fix things and share it with my fellow techicians.

        • Jestine Yong

          July 1, 2013 at 9:41 am

          No problem Waleed. Your expertise should be known to the world.


    • Waleed Rishmawi

      June 30, 2013 at 11:49 pm

      thanks Beh. yes you are right. the machine was dead any way. what more harm can be done. thanks for the encouragement and support.

  3. Ramputty

    April 16, 2018 at 4:05 am

    Hello jestine
    i am in trouble with my treadmill.
    i note the voltage at the bridge rectifier is 240 v and the Large filter cap also has 240-250 volt only - i expected the large cap to have 300v.and it take sone time to cahrge to 250 v DC.
    Please explain me what to check further.
    Do you have a guide to repair treadmill controller board -which i suppose is just like a SMPS,

    • Jestine Yong

      April 16, 2018 at 8:17 pm

      Hi Ramputty,

      The problem could be the main filter cap. Try check and if bad replace it. Sorry i do not have books in treadmill controller repair.


  4. Alvaro Goncalves

    July 29, 2018 at 10:25 pm

    I'm also in trouble with my treadmill
    The controller board is exactly the same type as the picture, but have the mos FET 1 & 2 installed.
    I give starting order and increase a little the speed on the motor goes to the max speed. I checked the speed sensor but is ok.
    Can you please give me some details to be possible analyze and sort it out the issue.
    Thank you


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