Sony VGX-XL2 User Guide (Computer Component) User Manual page 46

If you upgrade the memory by yourself and forget to close the inside
connector, insert the memory backward, or not completely seat the memory, a
failure or damage may result. Repair costs in these and similar situations will
be charged to the owner.
Contact customer support for questions about upgrading the memory. The
Sony repair centers provide a service for charge for those who can't install the
memory by themselves and for people who purchased or plan to purchase
Sony memory.
Sony Supported Memory Types
The following Sony memory modules can be installed in this device:
Capacity Speed Memory Module
512 MB DDR2 533 (PC2-4200) VGP-MM512J
Important Note: Always use DDR2 533 SDRAM DIMM VGP-MM512J.
Memory Capacity After an Upgrade.
Using Standard Memory: DDR2 533(PC2-4200)
Standard Upgrade
Capacity Bank 0 Bank 1
Standard (1024MB) 512MB x 2 DDR2 533
43 VGX-XL2A Digital Living System