Yeah, the time of death is a few years ago, they were cooked for a while...

Have you tried testing one module at a time at the original 3200?

I was going to suggest trying them at a lower clock but seems like you might be out of luck.

It is pretty rare to see multiple fails like this, do a search for your ram, mobo, chipset CPU and bios and see if anything flags. Might even be worth messing with latency settings, XMP can do stupid things.

Anyone already running memtest probably knows enough to check stuff but just in case.

Assuming it's a reputable brand it's probably worth attempting an RMA, it usually has pretty long warranty.

Wait, are you running it with the dead stick in?

You should memtest each stick on its own. Change settings in BIOS to match the sticks advertised speed. You might have to toggle XMP/DOCP on or off. Probably check timings and voltage, too.

And you're probably better off running 32 GB in dual channel mode. Unless you consistently use more than that, the extra speed is better than extra memory IMO.

If it's two sticks having issues, check if they are on the same channel. You might actually be having issues with your cpu not being fully seated. I had a buddy who could only ever get two of four to work, and it was a bent pin on the mobo.