Memory Not Recognized on iMac G5 2.1GHz, 20-inch DDR2

Bit Baby

Memory Not Recognized on iMac G5 2.1GHz, 20-inch DDR2

I have tried installing my new 2GB memory (Part Number CT518445) multiple times (face up twice, face down twice) and my G5 won't recognize this new RAM.  My G5 manual states to push the new RAM in until you hear and feel a click while the two rings partially go in.  I have done all of these steps and still nothing.  Please help.

2 Replies
Bank and Slot Hot Shot

Re: Memory Not Recognized on iMac G5 2.1GHz, 20-inch DDR2

'Face up and face down'?? The memory can only go in one way and one way only. They are keyed to prevent a user from installing the wrong kind of memory and from installing the right kind the wrong way. Make sure the outside memory clips on the motherboard are open, insert the memory so that the notch on the memory bottom lines up with the notch in the slot. Insert the module until the clips lock into place. This may take a little pressure. Once you've seated them completely, try powering the system up.

Kilobyte Kid

Re: Memory Not Recognized

I have a G5 Quad (4 x 2.5 Ghz power pc, running leopard) and following the crucial recommendation i have purchase two lots of 2x2GB DDR2 PC2-6400 (CT785041)


Following all instructions from manual, apple support website and crucial connected new memory into bank 2 and bank 3, with existing 2x2GB memory in bank 1.


Bank 2 does not recognise anything, either new memory boards or existing.


After testing all possibilities I now have one pair of the new memory boards in bank 1. Bank 2 empty. Bank 3 with new memory and bank 4 with memory which came with computer(PC2-4200) This ran fine for 2 hours, it then promted a shut down and restart and now it's only working bank's 1 & 4 with bank 3 not reading and bank 2 empty.


Is there something i can do with the computer on, options? settings? that can help. Do i need to strip them all out and re-try in the correct way (Banks, 1, 2, then 3) or is something wrong?


Thanks.  Stephen