Slots In Motherboard

The M.2 socket, used to connect SSD storage, uses the fast system, too (along with the third 16 lane PCI Express slot on this motherboard); however, on some CPU/motherboard combinations, the M.2.

I have been meaning to post this for a while, here goes finally.

Re: No expansion slots on motherboard? Wow, I wish I had known the expansion was so limited, but that's my fault for not researching better. I went on amazon and couldn't find much of a selection of the PCI Express x 1 slot configured cards. Memory slots on motherboard with CPU and chipset. A Memory slots on motherboard with CPU and chipset. Memory slots on the motherboard close up. Connector on the circuit board. The first one I encountered was a couple of years ago - I opened up a brand new ITX celeron board and I eventually discovered that one of the RAM slots was bad. The motherboard wouldn't boot with any RAM installed in one of the two RAM slots on the motherboard - remove RAM from that slot, and the system booted fine with RAM in the other slot only. Motherboards also have slots for RAM modules: sticks of volatile memory that temporarily store data for fast retrieval. Multiple sticks of high-speed RAM can help PCs handle simultaneous programs without slowdown. Full-size motherboards (like the ATX form factor) typically have four slots, while size-constrained boards like mITX usually use two.

I have a lot of system building experience, and generally held the belief that bad RAM slots on motherboards are uncommon. The first one I encountered was a couple of years ago - I opened up a brand new ITX celeron board and I eventually discovered that one of the RAM slots was bad. The motherboard wouldn't boot with any RAM installed in one of the two RAM slots on the motherboard - remove RAM from that slot, and the system booted fine with RAM in the other slot only. (Of course I had been storing the board for long enough that it was out of warranty, but that's another story...) I suspected a bad solder joint or tin whisker somewhere on the bad RAM slot, but my soldering iron was misplaced a while ago, and a visual inspection of the underside of the board looked OK.

I have been testing more boards than I used to over the past year, and I have found a number of other boards which have bad RAM slots, so I was wondering how many bad RAM slots others here have run into on otherwise good motherboards.
Also, has anyone ever successfully fixed a bad RAM slot, say with a solder reflow?
So far, in terms of failure modes with bad RAM slots, either any RAM in that slot is not recognized and ignored, or else the system won't boot with any RAM in that slot, either locking up during POST or black screen before POST, sometimes with beeps. Any time I have had memtest rack up errors, I have eventually traced it to an actual bad stick of RAM, but has anyone else noticed bad RAM slots causing other symptoms?

Slots In Motherboard

On dual processor Xeon boards I have further findings:

Motherboard Slots Identification

• If the blue (primary) RAM slot in a channel is bad, that whole channel is unusable
• If the first blue slot for a CPU is bad, that CPU socket is unusable
• If a non-blue slot is bad, usually only that slot is bad

What Is Pci Slots In Motherboard

Does anyone else have any experiences to add?