Question Pc wont boot in dual channel

[nickyfoxinbox]

Hello everyone!
I have a interesting problem, pc boots only on first RAM channel (A0,A1), but wont boot on B0, B1.
Pc specs:
mobo - Asrock b550m pro4, latest bios
cpu - ryzen 5 5600x
ram - Kingston 2x8gb 3200 (KF432C16BBK2/16)
gpu - rtx 3070ti zotac
psu - gigabyte 650w
Now the interesting part: All parts work fine in other PC's.
CPU works fine in other mobo, dual channel works
Mobo with different cpu works fine, dual channel works
Ram in other system works fine.
CPU and ram in different mobo's are working fine.
But CPU in original mobo doesn't work with any RAM in dual channel, only in A slot.
I have resetted bios, updated bios, checked cpu legs etc.
What should i do? Because i dont have any clues.

 

[geofelt]

Sounds like a cpu pin controlling dual channel on the motherboard might be bent or damaged.
Or, possibly a ram slot is damaged.
Looks like a replacement motherboard s in order.

 

[rickypicky5]

Sounds like a motherboard issue. If your motherboard is recently purchased, I suggest you RMA it.

 

[nickyfoxinbox]

Sounds like a motherboard issue. If your motherboard is recently purchased, I suggest you RMA it.

yeah, it's new, but it works fine with r5 3500 and r7 3700, so RMA isn't possible =(