the chips are soldered 2 in the first bank and 2 in second bank, yes i did change chip count to 4 and there is no much difference with that, i have some time now so i will try few things.
Please try everything I've suggested and post your results.
Ohh i forget to mention LED is always on. do you have same situation ?
I've reprogrammed the LED to be on when the board is doing work and to be off when the board is idle. This was handy during debugging of idle conditions encountered when all 16 chips are mounted. Also it's more informative. Some people like when a LED is flashing fast but in case of our board, that flashing doesn't really give you much useful information about the board condition. The primary purpose of LEDs is to display some information that can aid in diagnostics. I think that the "busy/idle" display is a good application for that LED.