early 2008 MBP won't start after new RAM

[KilGil27]

I installed this ram in my early 2008 15" 2.4 core 2 duo macbook pro today, and it won't start up if I have both sticks in at once. It works with one of the new sticks, and one of the old sticks, but then I only have 3 GB, not the 4 I paid for. Is this ram not compatible with this model or is something else wrong?

 

[pragmatous]

Probably defective RAM. Get it RMA'd.

I installed this ram in my early 2008 15" 2.4 core 2 duo macbook pro today, and it won't start up if I have both sticks in at once. It works with one of the new sticks, and one of the old sticks, but then I only have 3 GB, not the 4 I paid for. Is this ram not compatible with this model or is something else wrong?

 

[KilGil27]

Probably defective RAM. Get it RMA'd.

but would that only affect when both chips are in at once? because either one will work with the other old chip, just not together. curious...

 

[pragmatous]

Hmmm ...

Ahh I missed that part.

I've seen this in PC's quite often where one stick works but not both. I work in IT professionally and have been for 17 years. Usually updating the BIOS or UEFI resolves the issue. I'm not sure about macs. So yes it could be a compatibility issue.

Crucial has a very good memory detector app that will detect your system and recommend memory that is guaranteed to work. Crucial is a very reputable brand name. http://www.crucial.com/

newegg.com has a similar thing as well and will offer various brand names besides crucial.
http://www.newegg.com/MemoryFinder/

but would that only affect when both chips are in at once? because either one will work with the other old chip, just not together. curious...