The most common reason is that the contacts of the memory modules or the processor are oxidized. Since both the memory and the processor are usually not new, but used, this happens much more often than you might think.
- We carefully disassemble the system, remove the memory strips and the processor
- We wipe the contacts of the memory modules with an eraser, or with alcohol, galosh gasoline is also suitable.
- We examine the socket contacts, make sure that they are not bent. We also wipe the contacts of the processor.
- Collecting everything back and checking
The second most popular reason is incompatible RAM. LGA2011-3 only works with desktop modules with 16 banks (not chips). This does not concern server memory, it works all.
Check the characteristics of the available memory, if possible - check the modules on another PC.