RAM shows error in 3 of the 4 slots

[Stagnation]

I tested each of my 2 sticks individually and only 1 slot shows no error while the other 3 report errors starting from test 4.

Obviously that means if I want to run both my sticks I will get errors as well.

Is the correct conclusion that my motherboard has 3 bad slots or is there still a possibility of my ram being bad or perhaps some bios error?

[David (PassMark)]

If the stick works in some slots but not others, then it might be marginal (e.g. timings or voltages right on the edge of failure).
Probably more of a compatibility issue than outright failure.
Could try under-clocking or a slight voltage increase to see if it fixes it.