Power Inverter No Load (Idle or Standby) Current?

Hi Instructables members',
Case 1:
Recently build power inverter have a no load current vary 0.4 to some 4.0 amps (up and down or not stable) which causing the AC ouput also vary 230VAC ~ 235VAC.
Case 2:
My existing purchased inverter when switch on the no load current stay high. Some where 3 to 4 amps with the FET on power stage remove.
Do anyone experience this? Where shall I begin troubleshoot.
P/S: For Case 2 - earlier when switch on blown fuse. After change pre-boost FET, it no load current stay high.

Thank you for those valuable reply. Finally I found the problem.
Case 1:
Remove the fan and ad 100uF to ground at pre boost stage.
Case 2:
Replace an open transistor at pre boost board that driving the push pull fet.

Downunder35m2 months ago

AFAIK no inverter should be used without a load.....

tplim (author)  Downunder35m2 months ago

Yup I know. The no load current is on dc side upon switch on ther inverter.

Truenough these days..