old cpu memeory issues?

[orze]

so i have a old cpu from my old pc.

i had a massive mobo it used to sit in but a few days ago i found a mini itx mobo that fits it (its a i7 5820k)

now...i noticed wan plugging it in after what would be 3 years in my closet that only 3 out of the 8 ram slots work....

so i was sure the mobo must have got damaged while it was there

well the mobo dosent even boot.

 

can my cpu randomly get is memory chip or whatever it is fucked?

if not is there a way to fix it in some way or form?

kinda sad to see a 5820k go to waste i wanted to make a portable VR pc out of it.

 

for reference it was kept VAAARY safe in a container i got with foam i keep cpu's in...but im not sure what will make this....out of all the even older cpu's in that box to just lose memeory lanes...