S5520SC Ram problem

[idata]

hello,

i brought recently an intel s5520sc and 24 GB Intel-compatible Micron Ram (MT18JSF51272PDZ-1G4D1).

The first time i startet the pc everything works fine and the bios recognized the full 24 GB Ram. but after a restart it only recognizes only 20 GB.

i checked everything from the cables, to the cpus, switched the cpus and the rams, checked if there were some bent pins but there is nothing.everything seems ok.

what should i do?

the pc specs

2 x intel xeon 5670

24 GB Ram Micron (MT18JSF51272PDZ-1G4D1)

Quadro 4000

500 GB WD

DELL 30"

[DSilv11]

1) Make sure the BIOS is up to date ( Memory refrence code is in the BIOS so it controls how memory is reconized.)

2) Check the SEL log to see if you had memory errors and a DIMM is being marked as bad.

3) check BIOS set-up to see if all dimms are reconized.

[idata]

hey Doc_SilverCreek,

i checked the bios, it shows only 20GB, and the C1 Slot is Failed. I dont get it,

i changed the ram from slot c1 with another one, but again c1 is showing fail, so i dont thing that its a ram problem?

bios version is pretty new S5500.86B.01.00.0058

i dont know what to do?

[idata]

made the latest bios update to Version: 59;57;30;112

nothing happens;(

[DSilv11]

Sounds like a classic CPU bent pin.

Check the rear CPU socket paying very close attention to the right half of the socket. (All the pins associated with C1 DIMM are on this side)

Typically the bent pin is very easy to miss. Photo below shows one. Almost invisible execpt under magnification.

When the CPU is installed, the pin touches the adjacent pin and grounds out the memory channel

[idata]

hello Doc_SilverCreek,

i checked the sockets today and i found really no bent pins.

when i start the bios with the aptio setup utility i get this error codes: 8544 and 8524

someone any idea?

[DSilv11]

DIMM C1 BIST (Built in self test) is failing to set-up / configure the DIMM so the DIMM is being marked as "Bad" and taken off line.

Here is what could cause this error & your most of teh way down the list already. :

Bad DIMM

• Try swapping with another location.

Defective CPU / Debris on CPU

• I seen Heat sink grease on the CPU contacts cause issues like this
  • Wipe with rubbing alcohol
• and it is theoretically possible for a CPU memory channel to fail, (but I have never seen one do so)
  • If you have dual CPU's try swapping CPU's and see if the error follows the CPU..

Bad electrical path

• CPU Socket bent pin (97%)
  • Visual inspection and careful straightening of any bent pins
• Debris on DIMM fingers or in DIMM socket (3%)
  • Wipe DIMM contacts with rubbing alcohol.
  • Blow compressed air in DIMM slot.
• Defective mother board soldering.(<1%)<p> 
  • Replace Mother Board