Do you have a faulty DC to AC power inverter lying around? Don’t rush to throw it out just yet. With a bit of effort, you might be able to repair it yourself. This guide will provide you with step-by-step instructions on how to fix a power inverter.
Firstly, it’s important to note that the most common components to fail in a power inverter circuit are the MOSFET transistors. These usually burn out before the fuses blow. Therefore, that’s where you should start your testing.
The first step is to disassemble the case, remove the heatsink clamps, and slide out the main circuit board. MOSFETs come in a variety of packages, and this board has two banks of four TO220 packaged MOSFETs. It’s essential to identify them correctly and search for them online to confirm that they’re definitely MOSFETs.
To test the MOSFETs, you’ll need a multimeter with a diode testing mode. Place the positive probe on the gate pin and the negative probe on top of the heatsink, which connects to the drain pin. You should get a reading of one to two volts. If you get virtually no reading, the MOSFET is dead.
It’s possible to test the MOSFETs without removing them from the circuit board. However, if you need to remove them, use copper solder wick to remove the majority of the solder. Then, wiggle out the MOSFET pins with some thin nose pliers while still heating the solder pads.
It’s essential to use a decent soldering iron with 60 plus watts or a soldering station when removing MOSFETs. Although it’s possible to do this with a cheap 35-watt iron, you’ll have your work cut out.
If you find that you need to replace the MOSFET banks, it’s best to replace them altogether. Once you’ve replaced them, make sure to put some new thermal paste between the thermal pad and the MOSFETs and on the opposite side between the thermal pad and the main heatsink.
After reassembling everything, it’s time to test the power inverter. With no load, the multimeter reading should be good at 120.5 AC volts. To test it with a small load, connect a ground fault circuit interrupter for extra safety, then connect a low wattage device to see if it works fine.
In conclusion, fixing a power inverter might seem like a daunting task, but it’s achievable with the right tools and instructions. The power inverter, which cost the author around $160 five years ago, was fixed with just under ten dollars spent on four MOSFETs. With a bit of effort and patience, your faulty power inverter could have a second life.
So, if you’re faced with a broken power inverter, don’t give up on it just yet. Follow this guide, and you might be able to fix it yourself.