Question How does the motherboard exactly read RAM?

[Rockyhqk13]

I test returned motherboards for a liquidator. The ones I’m testing now are motherboards like Z370s, z390s, H370s, etc. All of them have bent pins. When testing, only 2 of the 4 ram slots work. I think I’ve figured out that most motherboards default to only Channel A working (DDR1?). This is way above my pay grade, but I’d really like to know how exactly do bent pins affect the Motherboad/Chip reading the RAM and how if one pin is bent, the motherboard defaults to reading them a certain way. I hope I’m explaining/questioning this the right way.

Also if someone can explain how the socket reads DDR1 and DDR0 and the difference between them, that’d be great.

Also I cannot find a clear photo of the pinout of the 8th gen socket. I found the Skylake Kaby 1151 but not the Coffee Lake 1151. I can tell they are similar but I would just like to have a clear, readable Coffee Lake pinout sheet.

Thank you!!

 

[TJ Hooker]

Most modern mainstream CPUs have dual channel memory controllers (and typically support two DIMMs per channel). Each channel will have a number of CPU pins associated with it. So if any pin(s) associated with a particular channel get bent, that memory channel (and the two memory slots associated with it) would likely cease to work.

 

[Rockyhqk13]

Most modern mainstream CPUs have dual channel memory controllers (and typically support two DIMMs per channel). Each channel will have a number of CPU pins associated with it. So if any pin(s) associated with a particular channel get bent, that memory channel (and the two memory slots associated with it) would likely cease to work.

Most pins, at least from what I can see on the pinout, read DDR1 and DDR0 data. So when one of the pins that read both, why does it auto default to the only working channel being A? (I think) But in motherboards where the RAM channels are staggered, (aka DDR4-1 is A1, DDR4-2 is B1, 3 is A2 and 4 is B2) it defaults to the first two slots only working or the last two slots only working.

Is each motherboard different in how it reacts to having a pin bent or broken? Or is it universal?