Hi,
I'm trying to repair a SkyTronic G-12-030 inverter (300W max), but without the schematics this may be a long shot
One of the Low (12v) Voltage MosFETs (RFP50N06) had blown. I have replaced it but still no joy.
When I apply 12v input, the unit just beeps, the fan is not turning, (I hear) no oscillation (I expect to hear a faint humming)
I noticed that a 556 timer chip did not get power, I also found a 7812 in the circuit. It also does no get any input power.
Any one any tips?
Schematics would be wonderful
Or does anyone know the OEM brand name of this unit?
Any tips are greatly appreciated,
ChrisV

 

Start by taking some photos of the inside, then we can assist you..

 

@Dodgydave ..
Thank you for your quick reply.
Good point about the photos. I will remember that for the next time

Just when I was about to give up and I had called the cavalry for help (this forum)... I found the issue...
I had to use a magnifying glass because my old eyes were hurting after staring for hours at that pcb, and... then I saw that I had missed a crack in the printed circuit.
Haha,... problem solved.
Happy days
chrisV

PS:
Take a look at the output signal on the scope, in the picture below, it is anything but a sine wave.