I built the same board with old sram and works.but could be there is an issue. Will scope everything.
You may wish to edit our C code and see what reads/writes to the SDRAM do. The hardware lets you talk to the SDRAM even if it’s not working quite right. For example, you can do a write, then do a read (with the cache off) and you’ll be able to see if bits are corrupted. When we were debugging this at first and finding the upper sdram speed limit (112MHz so we choose 100 MHz) we did manual pokes of the sdram to see what’s happening.
Note, with the stm.mem32 module you can do this in MircoPython.
Thanks for the tip. Our firmware guy is going to take a look.
Made other boards. Looks like there was a problem with the BGA contacts or the STM32 itself because all works fine with new and old sdram. @ercasta i guess you also have chips from unauthorized distributors… could have also been an assembly error . My assembler doesn’t have x-Ray to check properly.