Memory size in cmos invalid, Memory tests terminated by keystroke, No boot device available – Dell Precision R5500 (Early 2011) User Manual
Page 87: No boot sector on hard-disk drive, No timer tick interrupt

Memory double word logic failure at address, read value expecting value
Description
A memory module may be faulty or improperly seated. Reinstall the memory modules and, if
necessary, replace them.
Memory odd/even logic failure at address, read value expecting value
Description
A memory module may be faulty or improperly seated. Reinstall the memory modules and, if
necessary, replace them
Memory write/read failure at address, read value expecting value
Description
A memory module may be faulty or improperly seated. Reinstall the memory modules and, if
necessary, replace them.
Memory size in CMOS invalid
Description
The amount of memory recorded in the computer configuration information does not match the
memory installed in the computer.
Memory tests terminated by keystroke
Description
A keystroke interrupted the memory test.
No boot device available
Description
The computer cannot find the floppy disk or hard drive.
No boot sector on hard-disk drive
Description
The computer configuration information in System Setup may be incorrect.
No timer tick interrupt
Description
A chip on the system board might be malfunctioning.
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