Won't boot? Green light with usb charger

[deliveryninja]

My device with usb in has a green light on the back. I currently have a single battery as one is broken. 

First time I powered the device with the single battery and then placed the usb power cable in. I was adding roms to the device over wifi no problem. 
I went to the menu and selected restart the system. I can now not boot at all. 

Placing the cable in the devices gives the green light and the screen flashes. Same if the single battery is connected (screen also flashes when I connect this). 
I have held power button for 10 seconds and I get no response from the device. Tried all combinations of battery and usb and can't seem to get it to boot. 

Any help much appreciated thanks.

edit:
Just trying the power button with usb, the screen has gone white as if it was going to boot, front light goes green, but as soon as I move it goes off again.

edit2:
Taking off the cover seems that the power button is being flaky but even still I can boot to green light, screen goes black and it shuts off afterwards. Will try and format the sd card again

edit3:
Seems to have been a combination of resetarting the device, a dodgy power button and a corrupted sd card. Also it seems you can't power on the device from usb only with no battery connected

[Flavor]

You are correct. The Freeplay CM3 requires a battery to run. It will randomly shut itself down if you don't have one installed.

Do you think that you have the SD card sorted out now?

From our records, it seems that you have a 2pack of batteries. Here's a test for you.

Disconnect both batteries. Plug in power to the MicroUSB. The back LED should go green. Plug in one battery to one battery socket. The LED should turn blue (unless the battery is already 100% charged).
Disconnect that battery, and it should go green again. Plug in the other battery to the other battery socket. The LED should go blue again.
Connect both batteries to both sockets. The LED should stay blue. You can then let it charge until it is green.
[You could also fully charge one battery and then the other.]

This test will make sure both batteries are working.

I don't really know what's up with your power button. I guess there's a chance it was soldered at a bit of an angle or something. Early on in our first prototypes (when we called it the Game Pie Advance), there were a couple people that had to glue some bits to the slider to make sure it engaged well. That's when we were soldering by hand, so inconsistencies were more likely. It's possible that something like that happened.

[deliveryninja]

I have it up and working no problem with 1 battery. I've ordered 2 more actually as the black lead has disconnected from one of the batteries due to the force I needed to use to get the leads out when the build didn't work. I had actually shaved off the centre bar on the connectors but still required a lot of force. One issue is I hadn't opened up the battery pack enough to use the pliers to pull out the leads properly.

As for the power switch it seems to be behaving at the moment. I have just used the craft knife to cut small pieces of cardboard and place it under the switch to raise it.

SD Card is a strange one, not sure why it stopped working after doing a restart of the system from the retropi menu. Just a side note is to use windows disk management to remove all partitions before reformatting with the img using win32diskimager or it won't work. Using the power button to shutdown works fine.

[jakejm79]

Its actually the small nubs on the underside (if the center ridge is the top) outside of the connectors that you shave down, not the center ridge to reduce the force needed to insert/remove them.