comp wont boot up after adding ram!!

I assume it is just a typo and the old memory in the system is PC 3200 not 3500.

Have you checked the motherboard specs to see what kind and brand of memory is recommended? In particular- what latency and timings are required- or match to your existing memory? It looks like your maybe saying our old memory is CAS or cl 2 while the new memory is cl 3. If so this could be the problem. The memory should all have the same latency.

It sounds like you mobo has 4 slots and you are trying to add to more sticks in the open slots and they will not work.
Test the memory that works in the other slots and see if they work in those slots.
Test the new memory in the slots where they old memory was and see if they work there. Also try the new memory one stick at a time to see if it works.

Through this process you should be able to tell if the problem is the memory of the motherboard slots.

Usually the motherboard will pick up the settings from the first memory it finds (CAS2) - so it is probably trying to run the new memory at CAS2, and your new memory is only CAS3 so that's probably the problem.

Take the original memory out and put the new memory in where that was. If that works, put the original memory in to the empty slots. If that works, you're all set. If it doesn't, your second RAM slots are probably faulty.

hi,
well, no, that was not a typo! sad to say. thats what i get for going up and sewing when they placed the order! i wrote down ram for my comp, and left the comp i built to my son and hubby to buy ram for it.
we need pc3500 c2. not sure why they ordered what they did, but...
they spent all weekend trying to put that darn memory in, had 2 comp's taken apart (mine was one of them).
have to check newegg for memory again. maybe we will try 1gig sticks this time.
thanks
dumb blonde (w a bit of red) here  
suzy

So you've got 2 sticks of DDR-400 and 2 sticks of DDR-437. I'd say that's your prob. Your DDR-400 may not like running @ 437(217 mhz). You may have to manually set the timing to the slower of the 2 sets. Get CPU-Z to see the timings.
http://www.cpuid.org/cpuz.php

Your original RAM is very fast, but should have no problem running a bit slower to keep pace with the new RAM. Perhaps your memory speed/timing settings were not set to "auto" in the BIOS?
1) Reinstall only your original memory, boot the system and go into the BIOS. Make sure the memory speed and timings are all set to "auto". Save the changes to the BIOS settings and shut down. Boot again to make sure everything is working fine, then shut down again.
2) Now, install the new memory in the last slots. Boot up and hopefully it should work. If not, shut down and swap the new memory modules and the old ones. Try again. If it still doesn't boot, install only the 2 new modules and see if that works.

hi,
thanks! hubby will look at that hopefully soon. i am not the one who likes to mess with the bios.  

how about, i just foot a new newegg bill, and buy nice new memory? hubby can do what he wants with the 256 sticks. ( the 512's are in my comp).

so, should i just buy 2 sticks of 1gig? i would feel better if i had the exact ones to buy. i don't want my hubby to come back and say i can't buy the right stuff either!  
i paid over 300.00 for the orig corsair memory. how about some recommendations for 2 new sticks at about 150.00 or so?

i don't really want the ram to run slower, thats why i paid the extra money to get the fast ram. that's what the guys here suggested.

thanks
suzy

Your best bet for fast 2x1GB is probably something like this:
http://www.newegg.com/Product/Product.asp?Item=N82E1682...

I have the same problem.
I bought 4*512mb single sided memory, each has 8 IC on it.
So.
With 2 memory, in 1-3 DIMM slot, easily boot up.
With 2 memory, in 2-4 DIMM slot, easily boot up again.
With 3 memory, in 1-2-3 DIMM, boots again.
I make a test, with memtest 3.3, when 4 memory was installed. Until 72%, I got more than 450 failure notice. (130 in 7th test, and 324 in the 8th test)

Memory are the same, the serial numbers is continious...
I heard some IRQ settings, when someone install 4 memory into IS7. Anyone have this settings? Please give it to me, or tell something usefull  

Thank You!