Dell XPS 420 memory problem

[Prot]

I upgraded my Dell XPS 420 from the original 3 gig of RAM to 8 gig. It is a 64 bit quad processor, running 64 bit OS, and is running latest and greatest BIOS version (A07). There are 4 DIMM slots with 2 gig in each slot. Originally it had two 512 mb, and two 1 gig modules.

This is my problem. The BIOS reports there is indeed 8 gig of RAM installed, but I usually get memory address read/write issues at location BFE5xxxx at power up. This is just beyond the 3 gig mark on DIMM slot 2. MemTest86 only sees 1 gig on this slot, but sees 2 gig on all other slots, and Dell diagnostics only tests 3 gig of RAM. After 3-4 boot-up attempts, will boot.

As stated, the BIOS reports there is 8 gig of RAM, as does Windows 7. I have tried swapping out the memory modules, but DIMM 2 is still only seeing 1 gig of RAM, and errors just past this marker.

I would greatly appreciate it if someone out there knows of this problem and has a solution.

Thank you

[aedipuss]

i'd try increasing the memory voltage a tad and see if it goes away. you could also try slower memory settings in bios. next i'd take out the mem sticks and unplug the power cord and then use a vacuum with a brush attachment on the slot.

[Prot]

Normally I would agree that could be an issue, but what triggers my concdern is it is just beyond the 3 gig point, and the PC originally had 3 gig RAM. All four memory modules are new and are the same size and speed. The BIOS knows there is a 2 gig module installed, but only seems to be able to access the first gig (DIMM 2). MemTest86+ knows there is 2 gig, but only tests the first gig, again DIMM 2. It tests the entire 2 gigs on the other 3 DIMM slots.

This may be a BIOS/chipset issue, or the MB is faulty.

I also have a posting on Dell's community forum

[stiltman]

I would move the RAM around. See if the problem follows the stick or the slot
Are you using 5300 or 6400 RAM?
Not much you can do in Dell's BIOS, it's all automatic

[Prot]

I have tried moving the memory around. It is 5300 RAM.
My next test will be to decrease down to 6 gig with 1 gig sticks in DIMMs 1 and 2, and 2 gig sticks in DIMMs 3 and 4.
If I still get the errors at 3 gig mark, this will occur in DIMM 3 this time, making it a MB issue.
BIOS does see there are 2 gig sticks installed, but errors occur accessing beyond the 3 gig mark.
If this problem still occurs, it is a MB problem, and I will be considering a new PC. I used like Dell, but right now, I think they suck.

As stated, I am running current version of BIOS, but NOT most current Intel chipset version.

[jman98]

I could always be wrong, but I do think it is highly unlikely that your memory issue is a BIOS or chipset driver problem.

[Prot]

Swapped out DIMMs 1 & 2 with 1 gig sticks. MemTest86+ tests all 6 gig. Will leave PC powered off for a bit, then power back on to see if memory errors still occur. If everything is fine, then problem lies with DIMM 2 on the MB and nothing can be done; short of getting a new PC.

[Prot]

So far, no problems. I'll know for sure when I power up PC tomorrow morning.

[blinky88]

I think the problem is: the OS only uses 3 and a bit Gb, dedicates RAM to Graphics Card and other devises installed regardless of the amount of RAM installed.

[gallowayk]

No solution to offer, but I agree that Dell sucks. I had a problem with a USB controller on my XPS 420. It slowed down on posting so boots would take as long as 3 minutes. The trouble lights indicated a controller issue, and I ran the Dell diagnostics which generated an error code on the 3rd USB controller.
When I called Dell they wouldn't acknowledge an issue because a mouse plugged into one of that controller's ports would eventually work. When given the status of the diagnostic lights and the error code he refused to give them any consideration, and he refused to elevate the call to tier 2 support when I requested that he do so.
It seems that Dell thinks that go-no-go testing is all that's ever required. I disabled on-board RAID and now it boots fine so I'm thinking there's a conflict in the bridge controlling those controllers. It's a pain in the butt since I can't use SATA port 2 anymore, but at least I can use the computer until I get a new one, and it sure as hell won't be a Dell.

Wish I could help,
Kev

[Nelson37]

You should also try using just two, 2GB sticks and see if DIMM 2 will work correctly. It may be a maximum RAM limit. If it continues to see only 1 GB in Dimm 2, that pretty well nails it. I suppose you are out of warranty?

There is very little that can be done in Dell bios.

I would also check the slot very, very carefully, preferably with a bright light and magnifying glass.

[neomaine]

I think the problem is: the OS only uses 3 and a bit Gb, dedicates RAM to Graphics Card and other devises installed regardless of the amount of RAM installed.

The OP said he's using a 64-bit OS the full amount of memory is addressable. The 3.5ish limit is on a 32-bit OS.