Another RAM installation goes unrecognized....

Question

Have now made 3 attempts to install 2 new 1 GB sticks into Power Mac G5 Dual Core 2.0. There are two 1 GB sticks already in there that are working fine; these shipped with the computer. The new ones are said to be DDR2-533 PC2-4200 240 pin DIMM, unbuffered, non-ECC. They are made by Centon.
In Diagnostics, I read:
Power On Self-Test:*
*Last Run: 1/25/08 4:09 PM*
*Result: Failed*
*Failure type: Memory*
*Memory slots: DIMM2/J6900, DIMM3/J7000*
The memory slots read simply as empty in Memory.
Apple Hardware Test apparently was not supplied to me with my 10.4 disk set.
I just sent out a feeler to Centon to see about compatibility----their site has a 'memory matchmaker' click-through that suggests the ones I bought are correct for my computer....the packing slip that came with them suggests some potential differences or confusion....for example, the ones that shipped with the Mac are "2GB 533 DDR2 Non-ECC SDRAM", Centon packaging says nothing about the SDRAM part....additionally their packing slip says the sticks they sent are "267 Mhz" each although they are boxed and sold as 533 Mhz....
Anything I can do on my own to test or reinstall while I wait for a reply from them? anyone have experience, good or bad, with Centon products?
Thanks
EF

Answer 1

Hi
Apple Hardware Test apparently was not supplied to me with my 10.4 disk set.
The Apple Hardware Test is inside the same Tiger installation disc. You must restart your machine from the installation disc (pressing the C key) and you'll find it.
Ussually you must press hard the DIMMs to get them fine seated.
Besides that, you can try reset the NVRAM and PRAM:
http://docs.info.apple.com/article.html?artnum=2238
http://docs.info.apple.com/article.html?artnum=303124
Hope that helps !
  Alberto