An ancient proverb says that power tool failures occur in threes. During the same week that the lathe motor burned out and the compressor wire meltdown has turned it into a scary noise machine, we also had a mysterious malfunction in one of our welders. It didn’t release any smoke, didn’t make weird noises. It just didn’t weld. 0 volts across the output.

This machine, a small 180A TIG/MMA inverter welder, has recently been repaired. It was not used heavily, as TOG has only so much use for welding. In fact, it was only used by a couple members to practise their welding skills.
On one hand, this machine was 5 year old, has been used extensively in the past and could have been written off as death of old age. The cost of a commercial repair would probably exceed the value of the welder. On the other hand – why not try to repair it ourselves before scrapping it?


If you work in industry or business, you probably have your electronic test gear and multimeters calibrated regularly. If you’re an amateur you probably don’t. We don’t have a fancy calibrator at TOG which can cost 1000’s and need regular calibration in itself. We do however have a 2 Euro voltage reference based on an Analog Devices AD548 voltage reference. Checking some of the multimeters that we have around, and the results are surprising.
Our May Open Social evening takes place on Saturday 20th May from 7PM.