memory fault

Hi everyone, not been here for a while. I bought a second hand dell optiplex 320 for a spare comp. PenD xp sp2 2x256 mb ddr2 . It all worked fine untill I thought ............this would run quicker with more memory. I had a spare 1g of corsair 6400 800mhz , so I turned it off oppend it up and changed the two sticks for the one new one . After rebooting I got the 3,4 fault lights appear on the front. So i turned the pc on and of a few times and the problem stayed. I tried clearing the cmos and even replacing the old memory back but nothing reset the fault. Like I said I cant get to the bios or even boot cause as soon as it does its post checks it never gets past the memory fault. please dont tell me my mobo is dead:cry Any help would be great ,cheers.

 

Try switching back to the old RAM sticks. If that works, then either the new stick is dead or it is incompatible with the computer.

 

hi collins,"I tried clearing the cmos and even replacing the old memory back but nothing reset the fault." As I said in my post I already tried this first, as for the new stick it still works fine and yes there was a compatiblity problem. But I am trying to reset the fault. Advice from anyboby would be great thanks.

 

Sorry for my previous post. It will teach me to read posts more thoroughly.
/bashes head on desk/

Anyway, back to the problem. I've just had a look at the tech specs online, and it would appear that the system only supports DDR2 533MHz memory. This leads me to believe that the memory controller on your motherboard may be damaged.

 

Wait... the new memory, the single 6400, works fine? Then why do you think the motherboard is damaged? :confused

 

Hi mimsy, the single stick works in another desktop iv got, so I no its not that. Unfortunatley collins may be right. I did suspect this but was hoping for better news.