A Turkish Welding Machine That Does Not Weld Repaired And Maintained
A welding technician brought this faulty welding machine for repair. The technicians explained that while he was welding it suddenly stopped working although the machine was still on but no welding was being done.
Many technicians used this kind of machines for they are not too expensive to buy, durable and it can handle a heavy load of work;
the problem is they never do any maintenance work on it till it stops working and that is the wrong way to go.
There was no warning sign on it that something is shorted but there was not voltage reading at the output of the machine which raise the question why this is happening since all the IGBT’s and Diodes are testing fine, the relay is clicking, the screen and the fan is on?
One test would confirm the fault of this machine and that is by checking the pulse at the main IGBT’s; when I checked that there was no pulse whatsoever and that directed me to any area where the voltage is being generated near the main brain of the machine.
I took the machine board off, de soldered that faulty Mosfet and checked it for more conformation; it was confirmed that is was shorted and needed a replacement.
The part number is SVD9Z24NT.
Click above to download the SVD9Z24NT Datasheet
That is the exact location of the faulty part. I replaced the faulty part with a new one; put the machine back together for testing.
This time I was getting a healthy reading on the output of the machine and I this time my brother was not available to test the machine so I tested it myself and it was working fine.
The cause of this fault was over heating because the first time when I powered the machine it was shacking indication a faulty fan; one of the fan fins were broken causing it to rotate out of balance; it will not provide the right cooling for the machine causing it to overheat and shorting out.
I suggested a fan replacement for the customer but he was not interested at this time. I have a feeling that this machine will revisit me at any time.
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 HDMI TV Broadcast Switcher With Faulty Output Repaired and Maintained
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Albert van Bemmelen
April 26, 2025 at 5:32 pm
I guess that the defect mosfet was the fourth one of the other 3 still good also in parallel connected mosfets?
This way making a current possible of 4 times 12Amp at maximum?
Waleed Rishmawi
April 26, 2025 at 8:35 pm
Albert: that is correct my friend. Have a blessed day and thanks for commenting
Parasuraman S
April 26, 2025 at 6:40 pm
Good fix, my dear friend! There was no need for me to look at who wrote the article, the moment I saw 'welding...' at the caption. Many thanks for sharing!
Waleed Rishmawi
April 26, 2025 at 8:36 pm
Parasuraman: thank you dear friend for your nice comments and a very blessed day to you
Mark J
April 27, 2025 at 1:55 am
Waleed your the welding machine repair expert. Good job on the repair.
Waleed Rishmawi
April 28, 2025 at 4:10 pm
Mark J:thank you for your sweet comments. have a blessed day
Mick Mason
May 4, 2025 at 4:21 am
A great fix Waleed ! Well done.
I am always interested in your welding machine fixes as I used to be a welder by trade. I still have welding machines at home so I need to know how to fix them, should they fail at any time !
Many thanks for your repair reports !
Mick M, UK
Vladmir
April 27, 2025 at 6:27 am
Great repair.
How is Palestine
Waleed Rishmawi
April 28, 2025 at 4:11 pm
Vladmir: thank you. Palestine is fine. have a blessed day
Yogesh Panchal
April 27, 2025 at 4:13 pm
Waleed,
Good Job!
years of experience lead to the culprit in short time,keep going.
Waleed Rishmawi
April 28, 2025 at 4:12 pm
Yogesh: thanks man. yes experience goes a long way. have a blessed day
Jemba Alev
May 8, 2025 at 1:24 pm
Thank you sir, regards from Uganda Africa