Power Inverter won't turn on...troubleshooting steps?

[DainBramaged]

I have a DieHard 400W Mobile Power Inverter that I bought once-upon-a-time from Sears. I've never had any issues with it. Now, it refuses to turn on. I plug it in the cigarette-lighter hole, press the "On" and nothing happens at all.

Any ideas?

 

[LTC8K6]

Not enough power for it to turn on? Low voltage?

Blown fuse in the inverter or in the 12V outlet?

 

[LTC8K6]

Typically a 150 watt inverter is about all you can power from the 12v outlet in your vehicle.

 

[PottedMeat]

it should turn on with no load connected ( no 120V equipment plugged ).

if not, check the fuses for the 12v outlet ( look in car fusebox ), check fuses in inverter ( either in a little flip top fuse box on the inverter itself or by unscrewing the tip of the plug that goes into the outlet.

there also could be bad capacitors in the inverter.

...also do you need the key in ACC or on mode to get power to the 12 outlet?

 

[jagec]

Blown fuse in the inverter or in the 12V outlet?

First thing to check. Both those things (should) have fuses.

For the full 400W rating to apply, you'll want to hook it up to the battery directly, not through the power outlet.

 

[SearchMaster]

First thing to check. Both those things (should) have fuses.

For the full 400W rating to apply, you'll want to hook it up to the battery directly, not through the power outlet.

The fuse is often an in-line fuse in the piece that plugs into the outlet. I've seen them in the inverter itself but not usually.

 

[DainBramaged]

My iPhone charger works in the plug so it's not the 12V outlet. I also tried the inverter in another car, still no luck.

I took apart the inverter. There is no in-line fuse. I have examined the two fuses on the circuit board and they both look good. I don't see any blown capacitors. Would I see them, visually? I'm going to try putting it back together and trying it again. I just feel like I'm missing something.

 

[LTC8K6]

The fuse might be in the body of the cigarette lighter plug? They often can be opened and have a fuse inside.

 

[phucheneh]

There aren't a lot of options for reasonably-priced, small capacity inverters. They're pretty much all chinese crap. I'd just buy a new one.

There's no blade fuse in the actual unit? Like on a car amp? I would expect that. Or a glass fuse inside the cover.

Did you test the output of the unit with a meter? It may not be zero; you might see low voltage, which would likely indicate something wrong in the step-up transformer portion.

I'm no inverter expert, but I'd suspect two common failure points- the mentioned transformer generating the high voltage, or the transistors used to convert to AC. I'm assuming you've probably got a simple square wave unit.

If you don't see something obvious like scorch marks (can be on the component side of the PCB, or underneath with the solder joints and copper traces), I'd test the windings of the transformer with an ohm meter, and then check the transistors (google it- different types are checked different ways).

Also, examine any and all capacitors for buldging tops. A visual check is often enough for those.

If you make it to the small bits, like checking individual diodes and resistors, I'd just pitch the damn thing and get a new one. Cheapest parts, but least failure prone and often tricky to replace.