I was not intending to have this as as my first one here but because of the extensive number of ESP-07 modules released from factory with this problem I really hope will help people to solve the DOA issue without sending back the modules and receive brand new ones with the same problem.
So, basically, If you receive a brand new ESP-07 Module as in the picture above and when power up anything you get is a solid blue led light (power led on this type is blue) then maybe below is your solution:
1. Carefully remove the metal cover from the unit with a hot airgun.
2. Take a look at the oscilator near the ESP chip. If in NOT positioned as in the picture below then it need to be removed and resoldered AS in the picture. Mine were rotated at 90 degrees but might vary.
The problem was also posted and discussed here: http://www.esp8266.com/viewtopic.php?f=6&t=811&sid=da7df1aaf04aed5fa36a9dc41b22aa66&start=50
May your hot air station be with you !! 🙂