Hello again Zimmil,
It is good to hear from you again!
Since the replacement CPU did not work, there is a high possibility that the components on the Motherboard where the part is secured could be malfunctioning. Based on this information, I recommend contacting our technical support at 1-800-474-6836. If you live outside the US/Canada Region please click the link below to get the support number for your region.
http://www.hp.com/cgi-bin/hpsupport/index.pl
I hope this helps!
Regards