Guys, I have a bit of a problem: I decided to revive an old Medion desktop, it has an MSI MS-7829 motherboard, which for some reason stopped detecting RAM in the second slot. It all started when I simply wanted to add more memory so my child could play some simple games, but after cleaning the dust, the board completely refused to boot with two RAM sticks.

I have already cleaned the contacts and even reseated the CPU, because I heard that uneven pressure on the socket pins can cause memory channel issues, but nothing helps. Can someone tell me if it could be a damaged tiny component near the RAM slots, and which parts of the memory power circuit I should check first? Maybe someone still has a manual for it? Also, is there any chance there are hidden jumpers on the board that control frequency configuration? It is a proprietary board, BIOS options are almost non-existent, so maybe I accidentally touched something while cleaning?

Usually, Medion boards are quite reliable, but it can be somewhat vulnerable to ESD. And if washing did not make any difference, then probably a minor filtering capacitor or resistor network near the RAM slot might have gone bad. So to prevent randomly testing different parts with a multimeter, I think your best option is to refer to the service manual for MSI MS-7829 on this website ManualMachine. This lets you clearly see where the signal lines from the problematic slot go toward the CPU. And you can easily find the key test points, like the VREF and VTT power lines. By the way, have you inspected the CPU socket with sufficient illumination yet? Because a single slightly bent pin could be the reason why the second memory channel is not working. And it is almost impossible to find such a fault visually.