400 watt cheapy Canadian Tire Inverter

[Devo]

I have 3 of these that all let smoke out & then still worked for a bit before totally quitting.I had a bad connection to my battery terminal So when my wind mill would be charging it would allow it to "take off" for a bit this allowed the inverter input voltage to rise with the genny as the battery was effectivly disconnected.

It took a few inverters before I figured out what was going on.

At anyrate when I disassembled one & followed the power leads in the only thing I can find "different" is  the 2 large capacitors on the input have the tops rounded out away from them, like a dome roof. 2 others on the board are flat. Could this be the problem or how do you test one?

Trying to get these going again.

Thanks for any input

Devin

[nothing to lose]

I would say most likely "2 large capacitors tops rounded out" are bad, maybe other things also but pretty sure the caps are bad.

That is a big problem and one of the first things many of us look for when a computer board goes bad or the power supply dies. Caps normally have a flat top, many small caps  used on computers and other stuff for awhile were a bad batch, they dome up on top sometimes ooze out a goo and other stuff, when they are domed they are bad, sometimes stuff works ofr awhile yet, or sometime it may work then not work then work again later.

 I am geussing you have the same bad cap problem now but yours was probably caused by the over voltage on the input. Or you may have fried something else also first that caused the caps to go bad also?

It's hard to just look and see what's wrong with a circuit, but domed caps or fried traces etc... are a good visual start.

[ghurd]

Fixing cheap inverters is an excersise in lost causes.

Parts (& shipping) usually cost more than the inverter.

If the caps have a rating of 16V, I would expect the fets are cooked.

No good and short explaination. Just a hunch.

G-

[TomW]

G-;

Well said! Plus the obviously damaged part are not always the reason for a failure just a symptom.

Cheers.

TomW

[nothing to lose]

Ghurd, TomW

Your right, probably a lost cause trying to fix it. Anything else could be bad also on the board. I mostly meant if the caps are domed they are doomed.

Been awhile but I think my last 400watt cheap inverter was like $15 to $25 (USA) at most. Not hardly worth buying parts for and trying to fix unless just something you want to do to play with it.

Although if he has 3 of the same fried inverters he might want to play with them?

[Devo]

"Although if he has 3 of the same fried inverters he might want to play with them? "

You got it NTL.I will replace them & see what happens , I think it was 60 bucks for the inverters (each)-maybe a bit more when I bought them but they come on sale 1/2 price once & a while....-hopefully soon-lol.

Thanks for the help/input fella's , always appreciated

Devin