If it keeps going to the diagnostics screen it sounds like it can not find a bootable device. Most likely either the hard drive has gone faulty or windows need to be re-installed on the hard drive.
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To launch the diagnostics, press F10 during the boot sequence launch Lenovo diagnostics. Additionally, press F12 during the boot sequence to access the Boot Menu. Then press Tab to select Application Menu and arrow down to Lenovo Diagnostics and select it by pressing Enter.
If it keeps going to the diagnostics screen it sounds like it can not find a bootable device. Most likely either the hard drive has gone faulty or windows need to be re-installed on the hard drive.
This May Help,[br]
Peter