On my NEO-MVH MV2 (with stamp MVS V5 U) it is the 2 x 43256 SRAM chips (Sony CXK58256MM-12L) at 3H and 4H, just above the SP1 ROM.
A quick bit of continuity testing showed these are connected to the same address and data bus lines as the SP1 ROM. So, according to the pinouts for both, at a guess I would say 3H is this high byte. It could also be a WE, OE going to the RAM that is faulty as those are driven separately for 68000 addressing them as a word, hi byte or low byte.
If you have a different pcb version they may be elsewhere and/or different chip types.