HP Dc7100 HP Compaq Business Desktop dc7100 Series Service Reference Guide, 3r - Page 240

Activity Red Power LED flashes three times, once every second, followed by a two second pause. Beeps stop after the fifth iteration but the LED continues to flash until the issue has been resolved. Red Power LED flashes four times, once every second, followed by a two second pause. Beeps stop after the fifth iteration but the LED continues to flash until the issue has been resolved. Beeps 3 4 Red Power LED 5 flashes five times, once every second, followed by a two second pause. Beeps stop after the fifth iteration but the LED continues to flash until the issue has been resolved. Possible Cause Processor not installed (not an indicator of bad processor). Power failure (power supply is overloaded). Pre-video memory error. Recommended Action Check to see that the processor is present. Reseat the processor. Open the hood and ensure the power supply cable is seated into the connector on the system board. Check if a device is causing the problem by removing ALL attached devices (such as hard, diskette, or optical drives, and expansion cards). Power on the system. If the system enters the POST, then power off and replace one device at a time and repeat this procedure until failure occurs. Replace the device that is causing the failure. Continue adding devices one at a time to ensure all devices are functioning properly. Replace the power supply. Replace the system board. Reseat DIMMs. Power on the system. Replace DIMMs one at a time to isolate the faulty module. Replace third-party memory with HP memory. Replace the system board. C-8 361288-003 Service Reference Guide, dc7100