Things i have done after my last comment:
Testing individual mem. dimms with every stick i had on base, xmp, and on manual OC:
Slot 1+3, old ram = passes base, xmp, and manual timings
Slot 2+4, old ram = same result
Slot 1+3, new ram = passes base, xmp, and manual timings
Slot 2+4, new ram =...