James Sweet wrote:
JANA wrote:
Most likely some other parts that you did not change are also defective.
These are not worth servicing. I would suggest to buy a much better quality
inverter if you want it to last. You will get what you pay for.



While I would agree about buying a better one, that doesn't mean these
aren't worth servicing if you can do it yourself at home. They're not
very complicated and parts are not expensive. It can be worthwhile to
fix to keep it out of the landfill.

Well, I'd like to fix it, but I don't have the schematic diagram, and
there are 14 small transistors in there and a whole bunch of small
diodes. The 140 volt DC supply appears to be working but the modified
sine waveforms on the gates of the FETs are not correct. One is
correct, and another looks like a square wave with a very slight drop
that should be zero, and another two are low amplitude. I ohmed out a
few transistors but they all look good. Hard to figure out without a
schematic.

I went shopping at Harbor Freight and found a 1000 watt unit for $100
and a 700 watt for $50 and a 400 watt for $19.95.

-Bill