Thinkpad T520 with i7-2860QM, and CMSO16GX3M2A1222C9

Hello RamGuy,

My Thinkpad T520 is configured with i7-2860QM, and should therefore support 16GB, unlike the T520 i5 configuration in an earlier forum post. There are two easily accessed single-bank RAM slots in the T520, one on the back and one under the keyboard.

Accordingly, I purchased the 16gb kit (CMSO16GX3M2A1222C9), but one module is preventing boot. I can boot with the other one OK. I can also boot OK with 12GB, that is, with the default 4GB stick left in, and that one 8GB stick installed (and system shows 12GB being read). I also switched banks and re-seated modules carefully many times. Either alone or together, in either bank, I can boot fine with those two good modules (the default OEM 4GB module, and the one working module from the CMSO16GX3M2A1222C9). Only when the other 8GB module from the same CMSO16GX3M2A1222C9 kit is installed, in either bank, whether alone or with the default 4GB OEM also installed, does the T520 refuse to boot. That one 8GB module seems to be the culprit. The other 8GB module seems fine. There is also a beep code (1 short 3 long 1 short), which, according to Lenovo website is the RAM error code.

Presumably, I simply have one bad module in that CMSO16GX3M2A1222C9 kit. Should I go ahead and request an RMA number to exchange the kit?

-Much thanks, Paul T.