Precision M6500 won't boot when installing RAM in DIMM slots C and D

I can't seem to find a list of specs for "compatible" RAM.

I'm hoping I didn't waste a lot of money on this stuff. The modules all work fine in my E4300 as well, but it's only a two-slot machine.

Nothing? Really?

If the modules work OK in one pair of sockets but not the other, AND they're Dell-compatible memory, then have the mainboard replaced.

Ask the vendor of the RAM about compatibility - Crucial guarantees, as does Kingston with its KTD RAM.  If you bought generic RAM, the vendor is the best source of information.

It's Patriot but it's 1333MHz, my guess is that would be the reason. I'm swapping them for some Crucial 1066MHz chips.

Thanks.

I have the same problem and I bought crucial compatible ram upgrade for my precision and yet when I put the new ram in the slot c and d it doesn't boot. Crucial website did the scan of my pc and offered a solution for the upgrade.. so I guess is not a ram problem but a motherboard?

you have two new block. you have to put them in this order.. The old 2 blocks put them in A and C, the new one in B and D. or viceversa. the point is that they have to be alternated.. Example ( new: A,C; old:B,D) 

if you put the two new blocks close, like A,b or C,D it will not work, because the ram is probably not identic. 

Hope this will fix it.

Cheers

Just got off another call with dell.  After investigating or specs he has come to realize that with a dual core processor it will not be able to use slots C and D.  only the mobile quad cores can... =(

I have the same exact problems with 4 stock samsung 2gb chips. total of 8.  Any RAM in slots c and d will cause a boot failure.  I tried ram in JUST c and d and still does not boot.  Even one stick.   Will only boot when ram is located in slots A and B.  Dell came out and replaced MB and memory.  Still no luck.  Waiting for them to come back out or lemon the hole laptop.