I remember the old days, before RAM had little hydraulic presses to keep them in the motherboard… If you looked at the case wrong, the RAM would jump a mm so it was disconnected but still looked fine, or worse had an intermittent connection and would cause all sorts of issues.
Until it comes to seating RAM, or plugging/unplugging the 24-pin motherboard power cable.
I remember the old days, before RAM had little hydraulic presses to keep them in the motherboard… If you looked at the case wrong, the RAM would jump a mm so it was disconnected but still looked fine, or worse had an intermittent connection and would cause all sorts of issues.