I would take them to the same room and plug them in on the same power circuit. Do a factory reset and see if you can get them set up once again. If you can, then move them back into there spots for use and connect the devices to them. If after this and it doesn't work, something in between them is not working right on the power circuit possibly.
If you can't get them going in the same room using the same circuit, you'll need to phone contact DLink support and get help.
Keep us posted.