Electrical/inverter halp?

[I Lean]

Maybe a long shot...but I have this inverter that I'd like to function. I bought it used, and ended up getting a refund for it since it doesn't work--so I'm not out anything if I ruin it trying to fix it.

It's a GoWise Power PS1002. When you turn it on it beeps intermittently, and the "protect" LED is lit while beeping. Watch short vid:

At no point does it output 120V AC. I looked up the owner's manual, and it indicates an intermittent beep is the low-voltage cutoff, supposed to be at 10.6V. An over-voltage (>16V) would be a continuous beep. As you can see in the vid, input power is good. I've taken it apart far enough to look at internal connections and fuses, and all look good. (connections to the board are potted so I can't see them, but nothing is disturbed)

The only sorta-similar situation I've found in my searching, is a YouTube guy who fixed his inverter by replacing the mosfets. If that is the fault on this one, I can handle that amount of work--but I'm hoping there's a way to test, or confirm those are the problem before starting on anything.

Anyone have any ideas, or methods of testing, or any other input?

 

[1969honda]

Are you absolutely positive the bench test battery is good? We get a similar issue on the inverters in our fleet trucks when a battery has a bad cell, or a bad ground. Different brand but same issue.

The inverter kicks on, pulls juice for a second or two then kicks out when the battery can't support the amp load. Next the alarm and low input power light come on. Checking the battery voltage it'll be above 12 volts, but not by much.

Normally a cell in the battery has gone bad and simply changing batteries fixes the issue if one tests bad. After that is the game of checking ground cables for any loose or damaged connections, battery isolator allowing auxiliary batteries to not charge at full alternator output, etc...

 

[nnnnnate]

I have a dc lipo charger you could try if you wanted to rule out the battery.

 

[I Lean]

Are you absolutely positive the bench test battery is good? We get a similar issue on the inverters in our fleet trucks when a battery has a bad cell, or a bad ground. Different brand but same issue.

The inverter kicks on, pulls juice for a second or two then kicks out when the battery can't support the amp load. Next the alarm and low input power light come on. Checking the battery voltage it'll be above 12 volts, but not by much.

Normally a cell in the battery has gone bad and simply changing batteries fixes the issue if one tests bad. After that is the game of checking ground cables for any loose or damaged connections, battery isolator allowing auxiliary batteries to not charge at full alternator output, etc...

That's a good point, I haven't tried with a different battery. I THINK this one is fine, but it can't hurt to connect to one from another car. Do your fleet-truck ones have a load on them? (stuff connected to the AC side, I mean) I have a hard time believing the inverter by itself would pull enough amps to reveal a weak battery.

I have a dc lipo charger you could try if you wanted to rule out the battery.

View attachment 154823

I may take you up on that, I'll try a different battery first. I did consider using my charger's power supply for a minute, but it operates at 24V.

 

[1969honda]

Ours typically have Milwaukee battery chargers hooked up everyday, 5" grinders, occasionally an electric ground rod hammer (similar to a jack hammer), and at lunch time a microwaves. The 3500 watt inverter we use on 95% off our trucks is a full sinewave one with gfci 20 amp outlets, and lineman are known for over loading then and popping the breaker.

 

[Corban_White]

Very likely it's something on the board. Going to involve tracing the circuits and understanding/looking up what the components do. Probably not the mosfets, I'd imagine the input voltage goes through a sensing circuit and if it checks good then a relay closes allowing power to flow to the mosfets.

 

[I Lean]

Very likely it's something on the board. Going to involve tracing the circuits and understanding/looking up what the components do. Probably not the mosfets, I'd imagine the input voltage goes through a sensing circuit and if it checks good then a relay closes allowing power to flow to the mosfets.

That's kinda what I was afraid of. If I can't fix it by blindly throwing a few parts at it, it's probably a brick. Ain't nobody got time fo dat circuit-tracing stuff.