LINGQI power inverter over current ? shutdown

[tonydix]

I am trying to repair a LINGQI power inverter 800 watt peak and 400 watts continuous. The symptoms are as follows :-
Connect 12 volt battery gets a brief spark as capacitors charge the a steady 0.2amp on the clamp meter surrounding positive battery wire.
Switch on and led glows green for about 2 secs ac output voltage begins to rise then the led turns red and alarm sounds. Watching the clamp meter during this process shows an alarming rise in input current to about 30 amps despite the fact that there is no load on the ac output. Clearly something is shorted ! No visible signs of damage to FET's or Capacitors
Unit has 2 dil chips as control but part numbers are not visible. Any ideas about further troubleshooting. Thanks Tony

[stj]

Re: LINGQI power inverter over current ? shutdown

maybe a bad transformer.

[ben7]

Re: LINGQI power inverter over current ? shutdown

I am trying to repair a LINGQI power inverter 800 watt peak and 400 watts continuous. The symptoms are as follows :-
Connect 12 volt battery gets a brief spark as capacitors charge the a steady 0.2amp on the clamp meter surrounding positive battery wire.
Switch on and led glows green for about 2 secs ac output voltage begins to rise then the led turns red and alarm sounds. Watching the clamp meter during this process shows an alarming rise in input current to about 30 amps despite the fact that there is no load on the ac output. Clearly something is shorted ! No visible signs of damage to FET's or Capacitors
Unit has 2 dil chips as control but part numbers are not visible. Any ideas about further troubleshooting. Thanks Tony

I would say, check the power FETs and any power diodes there are in there.

Also, what does the output voltage rise to? Does it go too high?