they all have traces. if i use the 512's i have and know are good, i should install 4 right?

pic of existing cache

I'm a bit lost here. My pine pt-432b is saying bad cache or fails to boot. if cache is disabled it boots fine. there are 5 UM61256-15's plus 4 257's. None of the 4 jumper options for size work, being 125kb 32k8 x4 + 8k8 x1 , 256KB 64k8 x4 + 32k8 x1, 256KB 32k8 x8 + 32k8 x1 , 512KB 128K x8 + 32k8 x1 …

i have 486 pine pt-432b which is hanging during boot after finding the primary hard drive. the secondary is "not installed" in the bios config. will plugging a cd drive there fix that?

Hi I have a PT-432b/SR-M401-A which has a damaged um8667. I think its the FDD drive. Can anyone confirm what it is or have a datasheet? Some of the pcb pads were ripped off the MB. Most traces have enough for me to bridge but a couple i do not see where /if they are used.