Strange Memory Problem

I've never seen this before it seems really weird to me. I have this motherboard (SY-P4RS350) and if I use one stick of ram in either of the two dimm slots, it works fine. If I insert a second stick, it only detects whatever stick is in slot one. I have one 256mb and one 512mb and it does not matter which is in slot one, that is the only one detected. But if there is only one stick in use i can put it in either slot and it will be read.

EDIT: Its the SY-P4RC350 not SY-P4RS350

 

Have you tried to clean the memory slot? Could be that the modules are not making a good connection.

 

No it's not the connection because if I put either stick in either slot by itself it works fine, it's only when they're both in that there's problems.

 

Ok, what can you tell me about the memory modules themselves? Brand, Spec's, etc

Also, is this the first time you have tried to insert two memory modules?

 

Same Problem?!

I have the same motherboard. It does the same thing to me. I have an Ultra 1024mb pc3200 DDR 400mhz in slot 1 and a Kingston 512mb pc3200 DDR 400mhz in slot 2. Both modules work, but it only detects the 1024mb in slot 1. It's strange. Any input on how to fix this problem would greatly help, thanks.

 

A quick look at the spec on this board states that it support up to 4Gb dual-channel memory.
Have you considered that the board may be looking for dual-channel memory configuration, and may require ram of the same size to be inserted into each of the two slots in pairs (e.g. 2x512Mb in the first two slots and 2x512Mb in the second two slots, making up 1Gb in total)