I've got one of those 400W Noma backup units for my tank. You know, the gray-brick one. Tonight I turned it off at feeding time just like I always do, and when the time came to turn it back on it would not come on. >:(
Wondering if anyone else with one of these has had this happen, and if there was something that could be done?
how old is it? i know the battery's dont last forever, you get a few years out of it but you should still be able to turn it on even with a non charging battery. my guess would be power supply but you would need to open it up first to determine that.
Okay, so I fixed it. And I'll tell how, just for anyone else that comes across this in future.
If you are not familiar with electronics - especially high-current stuff like this - I would advise you not to attempt this. Take it to someone that knows how, and don't get yourself killed. I'm not responsible for you, but you are.
What I did was open the unit, disconnect the batteries (just the black terminals), let it sit for 10 minutes and then reconnect it. Back to working just like it did when it was new. 8)
My problem, just so you know, is that my Noma Backup Power 400 would not turn on. There were no error codes or other messages, and I could display the power remaining by holding down that button.
Before you start, make sure the unit is in it's 'off' state and not plugged into the wall.
1. Turn the unit onto its side. There are 4 visible screws in the corners (if you can't see them, turn the unit over) and there is one in the middle under the NOMA sticker. Run your thumb across it to find the hole.
2. On the bottom of the unit, there are 2 black things that look like buttons or something. You will need to get a small flat screwdriver up under each of those and pry them out of the casing. Save them for later replacement.
3. Unscrew all 5 screws.
4. Lift the casing up first from the top of the unit. It will come free, perhaps with a little trouble but not much. If you got all 5 screws and the 2 bottom pegs, there is nothing else holding the cover on.
5. Being very careful not to short any connections, remove the bolts/nuts from the battery connections that use black wire. Be careful not to lose the nuts into the lower part of the case. You can freely lift up the batteries and tilt them to make this easier.
6. The unit will probably beep once when you finally disconnect the second battery.
7. Walk away for a while, say 10 minutes.
8. Now you can reconnect the black wires, go ahead and do that, and when you're done you can try turning the unit on. Make sure you're not touching anything inside the unit when you do that, and it should not be plugged in, nor anything plugged into it.
9. Reassemble the unit.
There's actually a little computer in this thing that runs it, and by starving it completely of power for a short time, I believe I reset it.
Awesome. Glad you posted this.
I have 4 of the Noma 400's that I picked up on sale for $40 each. I keep two on my reef with a powerhead plugged into one and the heater into another, they also make a great portable power source and power bar as well.
Look identical to this one sold under Duracell.
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wher'd ya get those for $40?
CTC had them but that was a year and ahalf ago, I'm not sure if they carry the 400s anymore I think they only have the 150s.