Dell T1600 & SSD & diagnostic lights 2,3 + blue power switch

Hi

When I replaced the disk to SSD, diagnostic lights began to illuminate, number 2 and 3. It starts shining when "loading the system" appears on the screen.

Bios A21 settings:

SATA Operation: AHCI

uefi

Why do I have a disk error?

Regards,

Mateusz