Lenovo THINKCENTRE 6019 - Manual (Page 84)

POST Error Message Description/Action
Press TAB to show POST screen Pressing the TAB key permits the user to
toggle between the default POST display
screen and a custom POST display screen.
Error: Non-System disk or disk error
Replace and press any key when ready
The BIOS was unable to find a suitable boot
device.
Make sure the boot drive is properly
connected to the computer.
Make sure you have bootable media.
78 Hardware Maintenance Manual