Question Motherboard RAM problem

[KennyKB]

I have a MSI B760M-a motherboard and using 4x8GB ADATA XPG Spectrix D41 3200MHz DDR4 RAM. The system works normally when I populate A2, B1 and B2 RAM slots. When I populate the A1 slot Windows 10 refuses to boot although I can get into the BIOS. The BIOS shows that all 4 RAM slots are occupied and identifies the RAM correctly. However it refuses to boot into Windows. XMP profile is Disabled.

I've swapped RAM around and determined that all my RAM sticks are good. Is there any conclusion other than the A1 RAM slot on my motherboard is bad? Any insights will be much appreciated.

 

[Misgar]

I've swapped RAM around and determined that all my RAM sticks are good.

You won't know for certain your RAM is good unless you've given each stick a thorough (2 hour) test with MemTest86+. Errors can remain hidden in ostensibly "good" RAM until you run a comprehensive test.

Is there any conclusion other than the A1 RAM slot on my motherboard is bad?

It might the the CPU making bad contact with the motherboard socket, but A2 is working which implies the IMC channel in the CPU is OK.

Check all the contacts inside the A1 socket using a bright light, for signs of damage. You might find a bent contact.

 

[KennyKB]

You won't know for certain your RAM is good unless you've given each stick a thorough (2 hour) test with MemTest86+. Errors can remain hidden in ostensibly "good" RAM until you run a comprehensive test.


It might the the CPU making bad contact with the motherboard socket, but A2 is working which implies the IMC channel in the CPU is OK.

Check all the contacts inside the A1 socket using a bright light, for signs of damage. You might find a bent contact.

Thank you for your reply, Misgar. I didn't test my RAM sticks in depth but the if it can boot Windows I consider it fit for use.

All contacts in A1 DIMM slot seems normal.

With RAM in A2, B1 and B2 Windows booted normally. I transferred the RAM in B1 to A1 and Windows couldn't boot. I think that's definitive that A1 DIMM slot is the problem.

 

[KennyKB]

Update. I removed my CPU to check the pins on the motherboard socket. They were all good. After replacing everything I booted up the PC with all 4 DIMM slots populated and it booted into Windows. I think reseating the CPU may have solved the problem. I'm a happy camper now.

 

[Misgar]

Good to hear re-seating the CPU fixed the problem. Well done.

if it can boot Windows I consider it fit for use.

I tend not to check brand new RAM with MemTest86+, but any RAM I've obtained second-hand gets a thorough testing to weed out bad sticks.

I was gifted 60 sticks of DDR3 and 30 sticks of DDR4 pulled from office computers. Tests revealed several DDR3 DIMMs with hidden errors. Ostensibly the faulty sticks appeared OK, but would have corrupted data.

 

[KennyKB]

Good to hear re-seating the CPU fixed the problem. Well done.

It's counterintuitive. I thought re-seating the CPU will have no effect as the CPU can only go in one way and it's firmly latched to the MB. I actually took out the CPU to check for bent pins. Oh well...