A Shorted IGBT On A Cheap Welding Machine Repaired. Model: Sniper
A guy came to my shop and was looking for a good welding machine advice. He showed me a lot of models and brand name of machines but when I checked the specs on them, I did not recommend any of them since they are not good machines. Sad to say, because these machines are cheap, they are being bought by a lot of welding technicians and they end up with disappointment simply because they do not want to spend more money for better quality ones.
Against my recommendations, this technician went and bought this one which was the worst one in the group that he showed me. Guess what? It did not last a month and now it is in my shop for repair.
It was completely dead and from experience I am sure there is something shorted like an IGBT or some cheap component burnt up.
Someone has been in this machine because I could see a fresh soldering joint on the IGBT in this machine.
The part number is FGH60N60SMD which is an IGBT and I have seen this part before in many of the cheap welding machines that I encountered.
It is very clear that the IGBT is shorted
and it can be clearly seen on the display of the meter that bought and added recently to my shop.
This is a healthy reading of a good IGBT and if you compare the two reading you would see the difference in testing bad and good IGBT’s.
Right away, I replaced the shorted one with the good one, put everything back together and tested the machine.
17 volts is kind of low reading here and that is because it was still powered on through a current limiter. I took it next shop to my brother to test it out and it was welding fine.
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 article on Water Pressure Device Not Operational Repaired And Maintained
Tayo
September 10, 2022 at 8:18 am
It makes no sense for a person earning their living in a trade to even consider buying a low quality tool which is vital to their profession. Yes the initial cost maybe high but the money spent and lost fixing it when it breaks or remediating poor quality job that resulted from using the sub-standard tool will far exceed the cost of the good tool they are try to avoid buying.
There's an old saying comes to mind: "Buy Once, Cry Once" which is akin to "Buy Nice or Buy Twice".
Waleed Rishmawi
September 10, 2022 at 4:36 pm
Tayo: totally agree you with my friend. have a blessed day
Parasuraman S
September 10, 2022 at 9:17 am
Dear friend, can you please let me know the model number and make of the meter you are showing? I want to add it up to my workshop.
Many thanks for sharing your valuable experience!
Jim Whalen
September 10, 2022 at 11:29 am
it looks like this one. https://www.allelectronics.com/item/ctm-2/lcr/esr-component-tester/1.html
Waleed Rishmawi
September 10, 2022 at 4:40 pm
Jim: yes it is exactly the same and it is a very good one. have a blessed day
Jim Whalen
September 10, 2022 at 11:30 am
Portable MK328 128*64 LCD Transistor Tester Diode Inductance Capacitance ESR Meter MOS/PNP/NPN L/C/R Testing
Albert van Bemmelen
September 10, 2022 at 3:35 pm
Or here on Aliexpress
Albert van Bemmelen
September 10, 2022 at 5:04 pm
Probably all testers are based on the same old ESR tester firmware. Like the look-alike GM-328 or this one
Always watch out for charged capacitors before testing. They definitely will destroy the probably also AVR processor in your tester if not discharged first! The AVR microcontroller input test pins are very poor protected against higher voltages!
Waleed Rishmawi
September 10, 2022 at 4:41 pm
Jim: yes, that is the one. have a blessed day
Waleed Rishmawi
September 10, 2022 at 4:38 pm
Parasuraman: MK-328 TR/LCR/ESR tester. you are most welcome. have a blessed day
Yogesh Panchal
September 10, 2022 at 3:03 pm
Good Fix!Waleed
Waleed Rishmawi
September 12, 2022 at 1:30 pm
Yogesh: thanks man. have a blessed day
Albert van Bemmelen
September 10, 2022 at 3:31 pm
I guess that because of the poor design quality this welding machine will be back for more repair soon?
Henrique J. G. Ulbrich
September 12, 2022 at 12:47 am
Of course, Albert. And the worst: when the machine returns for a second service, the customer can wrongly say that the new problem is due to the quality of the first service. Anyhow, a Waleed´s good job. Greetings.
Waleed Rishmawi
September 12, 2022 at 1:29 pm
Albert: it might be the cause but I welcome any income coming my way. LOL. have a blessed day
Abigail Karonga
September 11, 2022 at 7:55 pm
Thank you techie friends,I am afraid to embarrass myself,but would appreciate if you could shed more light how the tester works or at least give reference we to an insight about this tool.
Jim Haden
September 12, 2022 at 11:12 am
Good job! I have a cheap plasma cutter which suddenly quit working to. Now I wonder if the problem could be something simple like this?
GIFT ELIJAH
September 14, 2022 at 10:35 pm
A very quick and good fix. The customer will keep paying for not taking your advice. Good fix