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wvc-600 crap

WVC-600 micro inverter repair: number 5

This is a followup about the fifth inverter that stopped working (and melted).

wvc-600 without caps
wvc-600 without caps

After removing the caps, we can see the amount of heat they must have gone through. No wonder why they blew up.

failing wvc-600 burned mosfet
failing wvc-600 burned mosfet

I’ve also desoldered and replaced one of the input mosfets, because it seems much darker than the others.

failing wvc-600 with heated traces
failing wvc-600 with heated AC traces

On this picture, we can see that the AC traces of the circuit board are too thin. They have heated up and started to burn.

WVC-600 strengthened circuit board traces
WVC-600 strengthened circuit board traces

So I’ve added to copper wires and solder to the AC traces on the back of the circuit, and to the Mosfets traces as well.

WVC-600 repair capacitors
WVC-600 new capacitors

Here is a view of the inverter with new branded low esr caps (Nippon Chemi-Con). They are ten millimeters taller, so I had to put some spacers between the case and the fan.

wvc-600 air cooling mod
wvc-600 air cooling mod

Here is the finish repair and mod of the fifth wvc 600 solar micro inverter, with the burn parts removed and replaced: input capacitor capacitors and connectors.

wvc-600 mod holes for air cooling
wvc-600 mod: holes for air cooling

Now it’s back in production and runs fine, apart the “MPPT stuck” problem that I still have to figure out, and the efficiency that is still crap. The temperature goes up to 31°C with two 300W pannels, compared to 45°C with only one panel before… and much more than 100°C with two panels!