Tl-wr740n

Recently I purchased a wireless router TL-WR740N and have some problems with it that goes something like this: I bought, I installed, I was setting in 2 minutes and go a few days (3), when my laptop shows an exclamation mark and can not navigate. Mention that all LED' s go, flashing. If you remove the plug, or restart recovers and signed for a few hours, but after that and I worry. I tried reinstalling version of the wireless card drivers, but nothing helped. If you help me I would be very grateful. Thank you!