Strange Problem with BF3 - DEAD AND NOT DEAD!!!

[spectrum]

I have a BF3 version 103 KJ154000, brought dead, I flashed it, put back the teh it never came up. But suddenly I noticed that it started flashing! The light will come up on the LCD and it bleeps too. This happens every 30/45mins.
Has any one experienced this strange behaviour before and how was it solved?
Thanks for any clue

[Porter]

Hardwar problem, try rehot power IC wyth flux.

[YamahaR1]

Remove shielding and reflow.
Fixed 10's with the same problem.