HP: Error codes

CAPS LOCK/NUM LOCK LED
LEDs blink 1 time – CPU not functional
LEDs blink 2 times – BIOS corruption failure
LEDs blink 3 times – Module error not functional
LEDs blink 4 times – Graphics controller not functional
LEDs blink 5 times – General system board failure
LEDs blink 6 times – BIOS authentication failure

Source : Blink codes on this page