Does memory has to match exactly?

[todesto]

I have 12GB in my system and wanted to add 4GB more so I got one.
But the system does not recognize the memory and shows slot as empty.

I have 4GB 2Rx4 PC3-8500R-7-10-JP (3 of this) and
the new one I got is 4GB 2Rx4 PC3-8500R-7-10-E1. the only difference is E1 and all others are same. Is this the problem?

or do I have defective memory?

 

[A Hobo]

I have 12GB in my system and wanted to add 4GB more so I got one.
But the system does not recognize the memory and shows slot as empty.

I have 4GB 2Rx4 PC3-8500R-7-10-JP (3 of this) and
the new one I got is 4GB 2Rx4 PC3-8500R-7-10-E1. the only difference is E1 and all others are same. Is this the problem?

or do I have defective memory?

check the slot for dust, then swap the sticks around, does the "empty" slot move?

 

[todesto]

check the slot for dust, then swap the sticks around, does the "empty" slot move?

Yes it does. Tried in slot 4, boot, shows empty.
tried in slot 1, boot, shows empty.

 

[rigormortis]

as i recently found out with a bad stick of ram , if their is anything wrong with the ram, the mac will refuse to boot

the ram manufacturer told me before sending it in for an RMA, that i should look at it under a magnifying glass to make sure their wasn't any broken traces

broken traces are not covered under warranty, they said

suggest returning ram / or getting it replaced under their lifetime warranty

i should be getting back a new stick in 3 days

i got a couple computers with different ram, my i7 has two types of ram cuz it is tri channel.

i figure it will work as long as the notch is in the correct location, and its not like parity vs non parity

 

[Thanks pal]

RAM usually has a lifetime warranty. Return it for another.

 

[rigormortis]

oh i forgot a good tip

before you submit a rma request or a return request
photocopy / scan both sides of that ram chip. you might need pictures of all the serial #s and part #s for your return/warranty request

when (name of ram company) told me about broken traces not being covered i made sure to email them high res scans of the ram module, heh

 

[A Hobo]

Yes it does. Tried in slot 4, boot, shows empty.
tried in slot 1, boot, shows empty.

then the stick is faulty. replace it.