So this may sound a little weird but hear me out.
คาสิโนสดUFADEALI've had a number of DIMMS (~ 15, a mix of DDR and DDR3) in storage for a few years (in the plastic cases they came in, mostly). These all have heatspreaders on, either factory fitted (most) or aftermarket (2). All of these DIMMs are now dead and will not run in any machine I test them in. They used to work in the PCs I had that supported them, but now, nothing. All my "naked" DIMMs without heatspreaders are fine. PCs that see regular use (DDR4, with heatspreaders) are fine).
What could be the cause of this? Thermal expansion/contraction? Something else?