HP DC7800 - Manual (Page 243)

Blank screen and the power LED flashes Red five times, once every second, followed by a two second pause, and the
computer beeps five times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause Solution
Pre-video memory error. 1. Reseat DIMMs. Power on the system.
2. Replace DIMMs one at a time to isolate the faulty module.
3. Replace third-party memory with HP memory.
4. Replace the system board.
Blank screen and the power LED flashes Red six times, once every second, followed by a two second pause, and the
computer beeps six times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause Solution
Pre-video graphics error. For systems with a graphics card:
1. Reseat the graphics card. Power on the system.
2. Replace the graphics card.
3. Replace the system board.
For systems with integrated graphics, replace the system
board.
Blank screen and the power LED flashes Red seven times, once every second, followed by a two second pause, and
the computer beeps seven times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause Solution
System board failure (ROM detected failure prior to video). Replace the system board.
Monitor does not function properly when used with energy saver features.
Cause Solution
Monitor without energy saver capabilities is being used with
energy saver features enabled. Disable monitor energy saver feature.
Dim characters.
Cause Solution
The brightness and contrast controls are not set properly. Adjust the monitor brightness and contrast controls.
Cables are not properly connected. Check that the graphics cable is securely connected to the
graphics card and the monitor.
Table D-6 Solving Display Problems (continued)
Solving Display Problems 231