MiSTer FPGA Forum

Hello all,

I also posted this on reddit so I apologize if some of you have seen this twice, but I would really like some help with this.

I recently ordered an SDRAM board from a reputable seller, and it has caused me some issues. I sent an email to the seller hoping they would be able to help me, but I'm going to copy it here to ask help of this community because at this point I am kind of getting desperate. Any help would be greatly appreciated.

"seller,

I recently purchased the 128 MB SDRAM from your store. I installed it today, and it has resulted in some strange behaviors. Previously I had a 32 MB board that I bought off amazon, which worked fine. I installed the 128 MB board and the Mister fails to recognize it properly (running memtest shows it only partially recognizes it, not the full 128 MB). No cores work with the board I ordered from you, including the Genesis core which does not require SDRAM. I reinstalled the Mister OS with no change in the issue. When I swapped back to my 32 MB board, it also is failing to be recognized (memtest shows 0, no memory detected), although the Genesis core does work with that board installed. This has me worried that it's not just the new board that is faulty. Any idea what could be causing this issue? I would hate to think that your board could have damaged my DE-10 Nano, but that's the only conclusion I've been able to come to so far. Please let me know if you are able to help."

Again, any help would be incredibly appreciated. Also I can provide more details if necessary.

Which memtest are you using? You can kill your de10-nano if you plug the memory module in the wrong way, but then probably nothing works anymore.

I was using the one that is installed using the update function, just called memtest. Both my original board and the new 128 MB board are clearly labeled which way they should face, and I was pretty careful about plugging them in the right way.

Can you post hi resolution pictures of the SDRAM board you bought and look for soldier bridges (shorts) on the board?
(Didn't realize up to now, that memtest also displays the size of the SDRAM)

If the board is seated correctly (gently wiggle side to side to ensure its seated with the DE10 nano turned off) you can test each 64MB chip by pressing the B key on your keyboard or press A for auto-mode which will auto-decrease the clock until stable in memtest which is how I stress-test my SDRAM after I build them. If none of that is working and you were careful removing your old module, good chance there is an issue with the module you ordered. Good luck!

If the old 32MB module is no longer recognized correctly either there is a defect in both modules or you have damaged the DE10. Do you have a friend nearby that could be counter tested?