Q: I have install some additional memory in my son Sony VAIO laptop, but seem to be having a problem. Its a VGN-C290 model (May 2007) and currently has one 1GB chip installed & has one open slot. It allows a max of 2GB.

Now, I have purchased an additional 1GB chip but after installing it in the one open slot, it appears that it is not recognizing it at all. The laptop will turn on, but doesn't get to the XP loading screen. even can not see the Sony VAIO/Phoenix welcome screen display.

 I tried the Crucial memory alone (without the orignal 1GB Sony memory) and still had the same problem.
how to update it. Anybody know if this is the latest version? I tried Googling it, but didn't have much luck. Or any other suggestions on what might be the problem here?

A: 1.please removing the sony memory and replace a Crucial memory to same RAM solt, Will it boot with just the 1 stick of Crucial memory?

then first install one memory stick and test. Separately install one memory stick to slot A and B once, so there are 4 tests in all for 2 memory sticks. If it wont boot on the Crucial ram and sony memory both for solt B,it is a problem with the sony laptop ram solt.

2. Do you have the proper speed of ram and is the sony ram the same speed? (PC2-4200 DDR2, 533MHz)

3. If you need a memory module from another laptop to test your laptop, please pay attention, the technical data guideline of the memory borrowed must be the same with the original one on sony memory.

From what googling told me it takes this ram and configurations.
Memory (Configurable)
2GB (1GB x 2) PC2-4200 DDR2, 533MHz