Couple of Problems With Custom Built PC

[Fragg]

Last year I built the following system:

Mobo: ASUS P5N32-SLI SE Deluxe ATX - nForce4 SLI X16Compatible (NVIDIA nForce®4 SLI™ Intel Edition)
Processor: Core 2 Duo (2.9)
Chipset type: NVIDIA nForce4 SLI X16
BIOS type: Award
Hard Drives: 2X WD / Caviar SE 16 / 250GB / 7200 / 16MB / SATA-300
RAM: Corsair TWINX 2048MB PC6400 DDR2 800MHz Memory (2 x 1024MB)
Graphics: Two XFXGeForce 6800 Extreme 256MB, SLI, PCIe
Case: GIGABYTE GZ-XA1CA-STB Black:Aluminum SECC ATX Mid Tower
OS: Windows XP Professional
Ran like a dream for a year--no problems.

Problem 1:
All of a sudden, my two front USB ports stopped working (started to get those annoying Windows pop-ups that there is an unknown device). I opened the case, disconncted and connected the plug from the front chassis USBs to the MOBO and restarted, and nothing--the USBs are still dead. Any ideas where the problem could be, on the mobo or on the case? Anyone ever have this happen before?

Problem 2:
My Mobo has four slots for DDR2 RAM. I originally put in two and recently decided to add another two (paired) and bought exactly the same type (Corsair) that was already installed on the system. I know that this version of Windows will probably only recognize 3-3.5 gig tops, but I put in both new RAM chips. When I fired up my system and checked the memory, it still only listed the original amount of RAM (it's like those two new sticks aren't even there). I made sure they were seated correctly and that the clips that snap down to hold them were all the way down, so I know it's in there. Any ideas why the system would not recognize the additional RAM? I upgraded my RAM on other systems before and never had this happen.

[CoolIce348]

What are the specs of your computer and what OS are you running?

sry I didnt see you already put the spec on there sorry, I just jumped down to your problem.

[Trotter]

Sounds like the USB ports have died on you. you said you had tried unplugging and replugging... did you try using a different header and get the same result? Case USB ports can be a bit shady somtimes. It happens.

As for the RAM, try swapping the new out for the old and make sure they work. then, put the new into the other sockets, but none in the ones you are using now. This will make sure that the hardware is working.

[Joeyboy]

unluckily i;d say the most likely reason for the RAM issue is two sticks of dead ram.

Like Trotter said you should take out your working Ram and put in the new stuff, if it doesn't recognize then dead sticks they be.

[Fragg]

Yeah, could be that the RAM TigerDirect sent was a dud. Other folks have told me the same thing. I'll swap out the old sticks with the new sticks and see what happens.

Regarding the front USB ports going dead--what do you mean by "using a different header?" You mean a different USB plug on the Mobo? Sorry, not as tech savvy as some.

[commandercup]

yeah, thats what he means

[Fragg]

Originally Posted by Trotter

Sounds like the USB ports have died on you. you said you had tried unplugging and replugging... did you try using a different header and get the same result? Case USB ports can be a bit shady somtimes. It happens.

As for the RAM, try swapping the new out for the old and make sure they work. then, put the new into the other sockets, but none in the ones you are using now. This will make sure that the hardware is working.

Okay--here's an update. I have four slots for RAM. My original RAM was seated on the two on the left and the two new sticks of memory the system is not seeing are seated on the two right slots. Computer boots fine, it just does not see the two new sticks.

Experiment One: Removed both sticks of original RAM on the left and left the two new sticks in the slots on the right. Computer boots fine, and sees the two new sticks. So it' not that the new sticks are dead.

Experiment Two: Put one original RAM stick and one new RAM stick in the left slots, and left the other two sticks out. Computer will not boot to Windows and gives me the following error:
"Windows could not start because the following file is missing or corrupt:
\windows\system32\config\system
You can attempt to repair this file by starting Windows Set Up using the original CD-ROM."

Experiment Three: Removed the one new stick of RAM in the left slot and replaced it with the other original RAM stick (back to original RAM two stick configuration). Left two right slots empty. Everything is back to normal, no errors, perfect boot to Windows.

Experiment Four: To the RAM configuration from Experiment Three, added just one stick of the new RAM to one of the open slots on the right. Computer will not boot to Windows and gives me the following error:
"Windows could not start because the following file is missing or corrupt:
\windows\system32\config\system
You can attempt to repair this file by starting Windows Set Up using the original CD-ROM."

Experiment Five: To the configuration from Experiment Four, I add the remaining new RAM to the last open slot on the right. Computer boots fine, but only registers two sticks or RAM. It's like the additional two are not even there.

Is there something I could do in the BIOS to make it see the memory? I've upgraded RAM on numerous systems, and the Windows environment always picked up the additional RAM. I've never seen anything like this before.

[nagasama]

take the old ram out of the right slots, and put the 2 new sticks in the left slots and see if they work.
you either have a bad motherboard, a bad stick/or sticks (yes i know that it booted, but it could still be bad), or a corrupt windows installation.
are you overclocked at all?
if you are, re-set EVERYTHING to stock. i get that message from time to time if i am trying to pull off a super overclock.
to me it sounds like a mobo problem, not ram....or some stupid windows ****.

[Fragg]

I'm not overclocked at all. System is pretty standard. I also don't think it's a problem with the MoBo RAM slots, since I was able to boot fine to Windows (and the system saw the RAM) using just RAM the right slots and just using RAM in the left slots. Considering that in my trials I only had the boot problem if I had one stick of new and one stick of old RAM or two stick of old and one stick of new--I'm leaning toward a memory incompatibility issue (even if the RAM is the same). I'm going to pull the old stick and the new stick and compare closely to make sure that there's nothing I missed. This is weird.

[nagasama]

okay, now that makes much more sense....you are only having the problem when the new ram is in...one stick or two. gotcha. the example post confused the **** out of me, to be honest lol.
what voltage are you running the ram at currently?
if it is stock, probably like 1.8V.
try turning that up to 2.1V
there are several xms2 ddr2 800 availible, and even though they "should" work at stock volts....doesn't mean they will.
post back, i am interested to find the solution to this.