Acer ZG5 does not support 2 GB memory because of onboard 512 MB. They put 512MB onboard an sodimm slot into same memory channel. And this channel can only handle 2GB total. If acers stupid engineers put sodimm slot to other channel. Max memory can be 2.5GB. damn ..
1536 max total memory is supported. The empty slot (after removal of the factory 512 that must be pulled first) can't take more than a 1gb stick (which is a pity). Needs to be PC5300 (533mhz) DDR2. The other factory 512 is soldered to the board (pity #2). Hope the soldered on stuff never goes bad! With dilusions of grandure I too tried to push the envelope and stuffed a 2gb stick in the expansion slot...same result...eternal blank screen. Even still, the extra half gig was an appreciable improvement because 192mb is being sucked away right off the top by the video. At least now the system has a good 1.3gb fully available after the video overhead. Throw in a 2gb SD or MicroSD also and dedicate it to SpeedBoost (im running Win7). This helps even more. Machine's quick enough at this point that I don't have any complaint. Runs Win 7 great even though it claims to be unsupported by this little machine.
Somebody from the 'how to' video said Acer One ZG5 can only take a max of 1.5Gb memory. It comes with a 512mb onboard memory and another 512 on the single memory expansion slot making up the total memory of 1Gb.
You can replace this 512 mb DDR2 SoDIMM with a 1Gb DDR2 on the slot underneath the keyboard/motherboard to get to a max of 1.5Gb. I tried to put a 2Gb DDR2 but the system just had a .single light and did not response/froze.
I have opened my Acer One three times to find this out by following this video and only needed to remove an additional three screws on the right side of the motherboard.. next to the hard disk so that I can slide the whole motherboard out/towards you to get underneath it..