Just a note of caution here about physically upgrading the RAM.
I posted this on another thread but it's relevant here, too:
"The amount of RAM is also limited by the BIOS so it's not just a matter of adding RAM. The BIOS would likely need reprogramming. I've run into this on systems like the Fujitsu B2630, which has 256MB of RAM that can be swapped out for 512MB but the BIOS won't recognize the new configuration."
Of course, I would love for the efforts to be successful so anyone who is brave enough to take apart their ADV3500PC and try to upgrade the RAM chips has my enthusiastic support.