Odd memory problem

[impudence]

I am having a strange problem with my fathers emachine computer. I noticed a month ago that his computer only shows 480mb of ram at boot and in the windows system properties. So I assumed that one of the mem modules on the stick that came with the computer had gone bad. Anyway tigerdirect was having a deal on memeory 19 bucks for another 512 stick. So I bought it for him and installed it, I left the old stick with 480 in it for a total of 996mb. Right away problems started showing up. Constant warning messages about unable to locate referenced memory at ... and programs like excel crash to desktop with no warning, and many drivers suddenly unistalled themselves including sound and video. So I run memtest and oddly no errors show up. Then I take out the old stick of memory and move the new one over, and oddly enough this new stick shows up as 480 also. It seems no matter what stick is in the first slot it shows up as only 480 mb. I have never in all my years messing with computers seen this problem before. I am assuming that the problem is with the motherboard, but I am wondering if anyone has any other ideas. Just so you know I have done a reinstall of windows and full virus scans, with no luck. The basic specs on the computer are emachines w2785 with amd 2700 and 996 mb ram.

 

[robisc]

onboard video sharing system RAM maybe?

 

[FlyingPenguin]

Agreed. You have onboard video and it's using part of the main memory for the video card. 32Mb to be exact, which is normal.

The new memory is either not compatible with the mobo, or is just not compatible with the other stick.

1 Gb is a waste anyway for anyone who's not a gamer or a power user so I'd just leave one stick in there - the original since that one was known to be stable on that rig.

 

[impudence]

ok update: I am a fool, I can't believe that I did not think of the video ram. I havent touched a computer without a video card in so long I forgot about shared video ram. However reliazing that has not solved my problem because the computer will not work properly with either stick in byitself. SO now I have no clue what is wrong. Any ideas? By the way, since the reinstall of windows the computer is really really really slow to start up now either with one gig or 480mb or ram it takes 3-4 minutes to get to the log on screen alone.

 

[FlyingPenguin]

Run MEMTEST86+ all night (at least 12 hours) to see if your memory is stable. I'd stick with the one original stick for now.

Check the gold contacts on the memory stick for crud. Corrosion buids up sometimes. If you see any, LIGHTLY rub it off with a NEW pencil eraser. A squirt of contact cleaner (WD40 would be okay, but contact cleaner is better since it leaves no residue) in the RAM SOCKETS wouldn't hurts if you did find some crud.

Make sure the RAM and cards are fully seated.

It's possible you cracked the mobo when you replaced the RAM. No hard to do if the mobo is poorly supported.