Got it sorted out. Thanks for looking.
Just in case someone's interested: the two secondary memory slots are a bit flimsy. They wouldn't hold the RAM modules well. Just bent the metal clips inwards (yes, you can do it; on my G51Jx-A1 the metal clips on secondary RAM slots do not have an outer plastic sheet in place) to ensure that RAM modules are gripped better.
G51Jx-A1 Does NOT Recognise RAM Module
Discussion in 'ASUS Gaming Notebook Forum' started by wmi, Feb 21, 2011.