recommendations aside (as to 1-2-3 ram slots) there is a lot of misinformation going on in the user manuals.I hope it's not a motherboard failure, but there was no issue with the old CPU. I think I will first try to move the sticks in the 3 other slots now that I know it's safe. Then if it works, that would point in the direction of a defective / dirty RAM slot and if it doesn't, I would have to look at the CPU / motherboard if I'm not mistaken.
such as "do not combine single rank with dual rank" or T7810 does not support 32Gb sticks.
i really don't get how these manuals are made.
or why arn't they updated.
if there is no risk of ruining something - give it a go.
(had a legion laptop - specs said max 16Gb ram, but i went with 24 - and read it could go to 32)