Help Testing 1000W AC Inverter

Thread Starter


Joined Jan 21, 2013
Could use a little help with troubleshooting a couple of, I believe, modified sine wave inverters, I have had them for a while and lately wanted to try repairing these.
I am currently working on a 1000W which has a board no. SP1000-1200H3 it's a Nikkai (also branded Skytronic I believe). It is supposed to give out
approx 240V AC, but at the moment all fault LEDs are on when input connected to 12V DC.
The device circuitry is based on a KA3525 PWM IC (14 pin), PIC16C72A microcontroller, LM324N Op. Amp.
I replaced all 12 primary side MOSFETs already, now I was wondering how to go about testing the various stages. I will post a follow up soon as I get some time to check some of the components and fault find this unit.
Thanks in advance,