HP Z4 G4 Maintenance And Service Manual page 57

Blank screen (no video).
Cause
Monitor is configured to use an input that is not active.
System appears to power on and fans spin, however there is a blank screen and the power LED flashes red three times and then
white two times, accompanied by beeps. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Pre-video memory error.
System appears to power on and fans spin, however there is a blank screen and the power LED flashes red three times and then
white four times, accompanied by beeps. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Pre-video graphics error.
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
System board failure (ROM detected failure prior to video).
Monitor does not function properly when used with energy saver features.
Cause
Monitor without energy saver capabilities is being used with
energy saver features enabled.
Solution
2. Expand the Resolution box, and then use the sliding control
to reset the resolution.
Use the monitor's on-screen menu controls to select the input
that is being driven by the system. Refer to the monitor's user
documentation for more information on the on-screen controls
and settings.
Solution
CAUTION: To avoid damage to the DIMMs or the system board,
you must unplug the computer power cord before attempting to
reseat, install, or remove a DIMM.
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.
Solution
1. Reseat the graphics card. Power on the system.
2. Replace the graphics card.
3. Replace the system board.
Solution
Replace the system board.
Solution
Disable monitor energy saver feature.
Solving display problems 49