Problem with first two ram slots on Z370-A motherboard

[Kobrakai]

I've just built a new PC with an Asus Z370-A Prime motherboard and I'm unable to get the RAM to work in the first two slots (DIMM_B1 and DIMM_B2).

If I put one RAM module in either of these first two slots and turn on the PC get I no output to the screen and the orange/yellow light appears next to DIMM on the motherboard indicating a memory problem. If I move the RAM module to either of the last two slots (DIMM_A1 and DIMM_A2) then it works fine. I have 2x8GB and I am able to install them in the 3rd and 4th slots but they will not be running in dual channel that way.

The RAM I am using is Corsair DDR4 Vengeance LPX Black, PC4-19200 (2400).

I have tried it with and without XMP. I have tried lowering the speed to 2133Mhz, and I have tried pressing the button next to the error light to detect the best settings for the memory. Besides this the PC works fine and I'm using it now as I type.

 

[Kobrakai]

I'm getting this with my Asus. Got it as part of the 8086 bundle and it'll accept one stick only .If I put two in, it either won't start or it only sees one stick.
If I put them in the other two slots it's fine. I can't be bothered to RMA it and as I've only got 16Gb it's not affecting me.

Do you have either the same memory or the same motherboard by chance? I'm wondering if there's been a bad batch recently or whether there's a general incompatibility. I've been trying to update the BIOS but the download links on the ASUS website are not working.

 

[Kobrakai]

Both of you check your pins in the CPU socket and also have either of you de-lidded or anything like that, the only reason you would have faulty memory slots would be damage to the CPU itself as that's where the memory controller is, or if it is the motherboard it will be socket pins, ram slot pins or motherboard traces from CPU socket to ram slots.

No I haven't de-lidded, I had to look up what that was as I've never heard of it before.

I checked the pins and it's hard to tell. Here are some pictures, I've marked the only place I can see where there could be a missing pin.

 

[Kobrakai]

Yeah it does seem that way. I don't see how I could have bent one pin right in the middle when fitting it though, surely it must have come like that?

I don't really want to RMA the board, and I don't think they will let me for a bent pin anyway as they class it as damage during installation.

Everything seems OK except the first two RAM sockets. I've done a stress test, memtest, etc. and it seems stable. I can run both 8GB sticks in the 3rd and 4th slots it just wont be in dual channel. From doing some research I think there's very little (if any) real world noticeable difference between dual channel and single channel anyway.

 

[Kobrakai]

I just spoke with the company who I bought the board from (it wasn't Overclockers) and they said they would take the board back only if the CPU had not been installed. I lied and said that I noticed the pin was missing after installing the motherboard but I had not fitted the CPU yet. The person I spoke to said that they would check the board to make sure a CPU had not been fitted. But how could they know this?