[SOLVED] BIOS not showing all installed memory

[rayians]

I just picked up a used AsRock FM2A68M-DG3+ complete with processor with 2x4GB Samsung DDR3 memory (sorry, I don't have the complete specs of the memory off hand but will add later). Anyway got everything together and running and installed Windows 10. It seemed to run great, but out of a hunch I checked This PC -> Properties and sure enough, it only showed 4GB of memory. I checked the bios as well, and it too only showed 4GB.

The motherboard only has two slots, so I started by swapping slots, and got the same result. I then installed one of each memory stick into each slot and the result was disturbing. With either memory stick in slot #1 closest the CPU, the PC booted normally. With either stick in slot #2 furthest the CPU, I got nothing at all, the monitor would not even power on.

The first thing on my mind is, could the memory slot on the motherboard be bad? What else could I possibly be missing? Any advice would be greatly appreciated. Thank you!

 

[Lutfij]

Yeah from the way you've mentioned it, the first thing I'd look at is a bad slot for ram if you're good to go with slot A1. But we need to look at other factors before putting in a nail(w/ blame) anywhere.

You failed to mention your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

Is this a new installation of OS or did you just migrate the OS from the old system? Which BIOS version are you on at the moment?

 

[rayians]

CPU: AMD A10 5800K
Motherboard: FM2A68M-DG3+
Ram: 2X Samsung 4GB 1Rx8 PC3-12800U-11-12-A1
SSD/HDD: Western Digital WD2500 HDD
GPU: Integrated AMD Radeon™ R7/R5 Series Graphics in A-series APU
PSU: Corsair CX750
Chassis: Cooler Master mid tower
OS: Windows 10

Is this a new installation of OS or did you just migrate the OS from the old system? Which BIOS version are you on at the moment? New installation of Windows 10. BIOS version was P1.80, I've already upgraded to P5.10 with no change.

 

[everseeker]

While you are at it, take a loupe (or good magnifying glass) and a strong light source.... and closely inspect the "bad" slot [Compare to the other one]
I have seen things like tiny bits of a sticker(Ram size) or bits of "Unknown cruft" blocking pins. I have also seen worse... wholesale misalignment and such, caused by a gorilla inserting a DIMM backwards or trying DDR2 (Yes, different size, different pinout... but still ...peeps DO try)

 

[Calvin7]

A10-5800K
Supported memory: DDR3-1866

Samsung 4GB 1Rx8 PC3-12800U-11-12-A1
https://www.amazon.com/Samsung-1Rx8-PC3-12800U-11-12-A1-Desktop-Memory/dp/B00HNP1OGY

Memory is DDR3-1600MHz, which is a slow speed for the A10-5800K.

Memory modules sold as Singles have no guarantee to be compatible in any configuration other than as Single modules.

Memory is guaranteed in the form sold. You should use a kit of two 1866MHz modules.