The Power LED on an HP Z200 Workstation is blinking red four times, once per second, followed
by a two-second pause. Which problem does this indicate?

A.
invalid ROM

B.
memory error

C.
power failure

D.
system board failure

Explanation:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&ta
skId=120&prodSeriesId=3718663&prodTypeId=12454&objectID=c01722872#en_wwi1012693(Topic:Diagnostic LED and audible (beep) codes)