HP Compaqdc 7600 chasis fan speed is variable and mostly runs at full speed. How can I tame it down?

SOURCE: HP D530 SFF CHASIS FAN NOT DETECTED

Should be an alarm setting, usually in the bios, for both chassis intrution and fan and cpu warnings. disable it and no error message.
Most likely the fan power is connected to the wrong fan port on the motherboard itself and placing it on the correct port will fix the issue.

SOURCE: Fans run at full speed under normal task.

THE PROBLEM IS THAT THE CPU AND MB AND PSU IS NOT COOLING OFF ENOUGH AND CAUSING THE FAN TO RUN ON HIGH ALL THE TIME, THE PSU MAY NOT HAVE ENOUGH WATTS POWER TO RUN THE CONFIGURATION TO KEEP THE SYSTEM AND HARDWARE TO COOL.

I READ IT IN ONE OF MY PC MAGAZINE, ANOTHER PERSON UPRADED SYSTEM, ADDED SOME OTHER STUFF BUT THE MB AND POWER SUPPLY UNIT DIDNT HAVE ENOUGH WATTS TO SUPPORT BASIC REQUIREMENTS OPERATING THE SYSTEM BASIC NEEDS.
FIND SOFTWARE THAT KEEPS EYE ON HEAT ISSUES, MB, VIDEO CARD, RAM, PS, CPU, CPU COOLERS, NIC CARDS, SOUND CARDS,
ETC.
EACH PART REQUIRES SO MUCH POWER
AND HERE HOW IT BRAKE DOWN FOR EACH COMPONET

MB 20-35+ WATTS
CD ROM 20-25 WATTS
DVD 30-45 WATTS
DISK DRIVE 5 WATTS
HD 5-15 WATTS
STANDARD VIDEO VARD 5-15 WATTS
MEMORY 5 WATTS PER MB

NEW SYSTEMS WITH THE FOLLOWING STUFF IN IT FLOPPY DRIVE,CD-ROM, MB, 16MB RAM, REQUIRES A MIN. 150 WATTS OF POWER.

BUT I KNOW YOU MAY HAVE TOP OF THE LINE VIDEO CARD WITH GGR4 WITH 512MB
MEMORY, 2-8 GIG OF RAM, 23 INCH LCD MONITOR, 2 500GB HD, BLUETOOTH AND WIRELESS NETORK, AND WIFI CAPABILITIES,
NEW DUAL CORE CPU TOP LINE MOTHERBOARD, COOLED VIDEO CARD,RAM COOLER ALSO AND THIS SYSTEM POWER WATTAGE REQUIREMENTS MAYBE SOME WHERE AROUND 400-600 WATT, AND MOST OF THAT IS FOR THE SYSTEM RAM AND THE VIDEO RAM YOU ARE RUNNING
REMEMBER 5 WATTS PER 1 MEGABYTE OF
RAM
IT WILL ADD UP FAST BOY'S AND GAL'S

ROD

PS I HOPE I DIDNT BORE ANYONE,
IT MAY SAVE YOUR SYSTEM FROM BURNING UP.

SOURCE: no signal to monitor, fans run full speed

maybe your cpu is faulty or ... maybe power suply ??