|What do you mean by "loses power"?|
If you mean the power quits and the unit shuts down, that's a hardware issue, replace the unit.
If you mean the wireless stops working properly, but computers plugged in with a network cable to a LAN port are still able to surf and communicate just fine, then that's another issue entirely and has nothing to do with power.
If the latter is the case, try updating the firwmare to the most recent version available if it isn't already up-to-date. If that doesn't fix the issue, try resetting it to factory defaults (manual has this information) and reconfigure it.
If none of the above works, replace it.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.