[SOLVED] P7P55D-E Unrecognized Memory

[buschbarber]

I built a PC 9 yrs ago, for a friend, with an Asus P7P55D-E mobo and 2 G-Skill 4Gb memory modules. This week, he called to say he ordered 2 more 4Gb modules and wanted me to install them. When I arrived, the PC was on, and I noticed that Windows 10 only recognized 4Gb. I powered off the PC. The first two modules were installed in slots A1 and B1. I installed the two new identical 4Gb modules in slots A2 and B2. Upon rebooting, the Bios only recognizes 8Gb. Windows Task Mgr says 8Gb in 2 slots out of 4 slots. I looked at the Asus mobo manual and it says I can install a single module in either slot A1 or B1. Using one module, I installed it in slot A1. The PC would not boot. I Installed it in Slot B1 and it booted fine. I am not sure if I need to press the Mem OK button and when. It says it will not work in the Windows OS so I assume you should only use it when in the Bios Setup Utility.

 

[rgd1101]

so half the ram slot failed?

 

[buschbarber]

Only half the ram is being recognized. Based on testing with individual Dimms, I am just asking if the mobo slot A1 could be bad? If I put Dimms in A1 and B1, the Bios only recognizes 4Gb..

 

[rgd1101]

if you tested with the same ram that work in B1, then yes, it bad

 

[buschbarber]

OK, then my only option is to live with less memory or purchase a new mobo? There is no possible fix to a memory slot?

 

[rgd1101]

could be anything from the slot to the memory control

 

[buschbarber]

What do you mean by the memory control?

 

[rgd1101]

I mean memory controller

 

[buschbarber]

Where is the memory controller and if that is the problem, can it be corrected?

 

[rgd1101]

memory controller is in the cpu.
But also could be issue with the motherboard.

 

[lynx1021]

That motherboard can only support Dual Rank 4GB memory modules, Low density, double sided. ADATA ADDU1600C4G11,G.SKILL Value 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-1600C11D-8GNT or Discontinued Ballistix Sport 8GB Kit (4GBx2) DDR3 1600 MT/s (PC3-12800) UDIMM 240-Pin Memory - BLS2KIT4G3D1609DS1S00

 

[lynx1021]

Bent pins in the CPU socket can make some of the memory slots not work.