T400 - is this memory compatible? My laptop won't boot

I just got a T400 through work. I ordered more RAM for it because it didn't have much when it was given to me. I wanted 6g for running VM's and such. Below is the link to the two modules I ordered. Are they compatible together?

I can run either module by itself, but when I put them in together, the machine just beeps and will not attempt to boot.


Crucial 4GB 204-Pin DDR3 SO-DIMM DDR3 1333 (PC3 10600)

Crucial 2GB 204-Pin DDR3 SO-DIMM DDR3 1333 (PC3 10600)

These look like the exact same thing to me, but different sizes. I've tried putting the 4g module in slot A and the 2g in slot B. It won't boot. I reversed them, and it still won't boot. I can boot either of them by themselves in slot A, they just don't work together.

 

The T400 doesn't support PC3-10600 DDR3 RAM (1333MHz), only PC3-8500 1066MHz RAM. However, the sticks you put in should technically be downclocking to the appropriate speed, so that's kind of funny that it won't boot at all.

Specifically, what are the beeps like (ie: single beep, two beeps, etc)? I assume it doesn't make it to BIOS?

 

while, theoretically the memory should downclock to the appropriate speed, but in some of cases they don't, so this is why you should buy compatible speed ram .

 

This is obvious problem when RAM have various Cas Latency.

Correct link for 4gb module.

 

I only ordered that because Crucial.com says PC3-10600 is compatible. I didn't know it would be downclocking. Figures. Looks like I'm going to owe NewEgg a restocking fee.

 

This may sound odd, but check they are installed properly.

Sometimes if the connectors don't push in correctly, you can think it's installed when it's not.

 

I tried it half a dozen times every which way imaginable. No dice. I just ordered PC3-8500 modules and will send these back.

 

Had to ask the obvious You'd be surprised at how often this fixes things

 

The best thing to ensure compatibility in dual channel mode is to use identical rams not only in size but both model, chip & density. I believe the issue is not the memory speed but the mismatch in size. I would have sent the 2GB back instead and opt for another identical piece of the 4GB and Im sure it would work.

 

You don't have to run memory in dual channel mode, but you are correct that sometimes different sticks have oddities with each other.

My crucial 2gig sticks mixed with a 1gig Samsung stick that came from Lenovo will have random artifacts showing up on the screen. But with both crucial sticks, 2x2gig, it is fine. And the 2x1gig Samsung sticks work fine as well.

Hopefully proper speed ram works. Does anyone know if the 4gig had a different latency?