Memory Upgrade, VGN-A250 won't boot

The A250 comes standard with the 2x256MB configuration, upgradeable to 2X1GB. I decided it was time to max out the Vaio, so I purchased some Samsung PC2700 modules and eventually figured out where the hidden slot was, only to find that my laptop won't boot with both modules installed. The computer powers on, then you here the hard drive turn off (as well as seeing the LED go out). I tried disconnecting the battery, the BIOS backup battery, the 5-minute wait, the BIOS reset (F2 from boot), no luck. I can run the machine with one of the new 1GB modules in the keyboard slot and either nothing, or one of the original 256MB modules in the undercarriage, and the system boots up fine. It is when I attempt to install both 1GB modules that the laptop does not boot.

Anyone heard of this specific issue? I know both modules are good because I swapped them and ran them alone with no problems. Additionally, I contacted the online Sony Analysts, but they ended up suggesting a servicing, which doesn't make sense to me if both slots can recognize memory.

Thanks for any info you have.
-b2b

 

bump bump bump

 

Hi Brad,

The Intel 855PM Memory Controller on your motherboard was designed to accept 2GIG Max of DDR RAM. The problem is that the 2 GIG limit will not be reachable because the Sony engineers only incorperated 2 banks for memory expansion on that motherboard.

So in essence, the Memory Controller chip can handle the following:
4 banks @ 512mb each = 2GIG of Max RAM.

What that means for you is becuase that motherboard was designed with only 2 banks (or expansion slots) it can only utilize 2 x 512mb RAM.

So, you can only install a max of 512mb x 2 and get it to work properly (with both slots filled)


Joe K
www.aqstech.com

 

well what about 2 x 1 GB?? I don't understand why I can't do this...when I can do 1 x 1GB + 1 x 256MB.

 

It turns out one of the DIMMs must be defective. I thought that I had tried both out individually, but apparently I did not. When I took the VAIO into Sony Style (nearly a year after the reported problem), they were able to boot up my laptop using the 1 GB DIMM I had installed plus one of their own.

-b2b

 

You could have discovered that yourself by running a memory tester. It's a good idea to do that whenever you make changes to memory.

 

It turned out to be a defective memory module.