Something has packed a sad this evening and my desktop won't post. It has gone into a boot loop and shows an error code on the motherboard.

Motherboard as per subject title, Ryzen 7 CPU, 32Gb (4 × 8Gb) of Corsair DDR4, Evga 1070 hybrid graphics.

Was running perfectly fine last night, shut down without any drama. Only thing that has changed in the last week was two new screens on Friday. Power up this evening to no avail.

On boot, the seven segment display shows "54" which, according to the manual is:

50~55 Memory initialization error occurs.

I've tried just about every combination of different sticks in different slots, to no avail - the boot loop continues.

I've tried the backup bios, I've cleared the cmos. I've unplugged every peripheral and tried cycling the memory through different slots again. I've reseated every connector bar the CPU itself.

Two sticks of memory are maybe 4 years old, the second two perhaps 4 months.

Any suggestions would be most welcome.