[DTech]

It would be easier to install all missing components and then test, so instal an original oki, au5780a and original TJA1054 the one your board came with. Maybe memory modules have to be samsung and not any other brand.

Memory chips are not limited to Samsung at all. I think that you already saw the picture provided with Cypress memory on original interface. All you need is to respect the type of memory ,speed and voltage.
Based on that fantomel already provided compatibility list from all providers in his rework and from those in our days ISSI is the one you can find easy.

P.S. Attached is picture from original interface with CY7C1041D-10ZSXI memory chip and a compare with current revision of it and ISSI one to make for all choosing more easy.