HP Designjet 500 and 800 Series Printers - TWI: No Front Panel Display

The TWI Designjet Documents library presented here as a courtesy of ComputerCareOnline.com

Part Description	Designjet 500 Model Numbers – C7769B, C7770B, C7769C, C7770C	Designjet 800 Model Numbers –C7779B, C7780B, C7779C, C7780C
Power Supply (Required)	C7769-60145	C7769-60145
Front Panel (Required)	C7769-60161	C7769-60161
Electronics Module (Required)	C7779-60144 / C7779-69144	C7779-60144 / C7779-69144

NOTE: If Removal and Installation instructions are needed for reference during any repairs performed, refer to the 500/800 Series Service Manual available download.

Troubleshooting steps (for Designjet 500 without an HP-GL/2 Accessory Card)

If any of the troubleshooting steps listed below solve the problem, attempt to verify printer functionality (instructions below). If functionality is verified, no additional parts should be replaced.

Turn the printer on and listen for internal printer noise (fans, carriage movement, etc).
If internal printer noise is observed after being turned on, continue with Step 9.
If no noise is observed, continue with Step 4.
Disconnect the printer from any surge protectors, universal power supplies or other similar devices and connect the power cord directly to a wall outlet.
Turn the printer on; if problems persist, try another wall outlet.
If unsuccessful, try another power cord (if available).
If the printer does not respond, replace the Power Supply (refer to pg. 8-27 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below). Continue with the remaining steps if the problem persists.
Follow the instructions below to increase the contrast settings:
1. Unload any media. Turn the printer off then on (allow 50 seconds for printer initialize).
2. Following initialization (when printer is quiet), press the Down Arrow three times, then press Enter.
3. Press the Down Arrow five times, then press Enter.
4. Press the Down Arrow two times, then press Enter.
5. Press the Up Arrow ten times, then press Enter.
6. Press the Back key until Paper Menu appears.
If the printer display is now visible, the contrast settings were turned down. Verify printer functionality as described below.
If the display is still not visible, replace the Front Panel (refer to pg. 8-9 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below).
If the problem persists, replace the Electronics module (refer to pg. 8-24 of the 500/800 Series Service Manual).
Following replacement, verify functionality as described below.

Troubleshooting steps (for Designjet 500 with an HP-GL/2 Accessory Card)

If any of the troubleshooting steps listed below solve the problem, attempt to verify printer functionality (instructions below). If functionality is verified, no additional parts should be replaced.

Turn the printer on and listen for internal printer noise (fans, carriage movement, etc).
If internal printer noise is observed after being turned on, continue with Step 9.
If no noise is observed, continue with Step 4.
Disconnect the printer from any surge protectors, universal power supplies or other similar devices and connect the power cord directly to a wall outlet.
Turn the printer on; if problems persist, try another wall outlet.
If unsuccessful, try another power cord (if available).
If the printer does not respond, replace the Power Supply (refer to pg. 8-27 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below). Continue with the remaining steps if the problem persists.
Increase the contrast settings as described below:
1. Unload any media. Turn the printer off then on (allow 50 seconds for printer initialize).
2. Following initialization (when printer is quiet), press the Down Arrow three times, then press Enter.
3. Press the Down Arrow six times, then press Enter.
4. Press the Down Arrow two times, then press Enter.
5. Press the Up Arrow ten times, then press Enter.
6. Press the Back key until Paper Menu appears.
If the printer display is now visible, the contrast settings were turned down. Verify printer functionality as described below.
If the display does not become visible, replace the Front Panel (refer to pg. 8-9 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below).
If the problem persists, replace the Electronics module (refer to pg. 8-24 of the 500/800 Series Service Manual).
Verify functionality as described below.

Troubleshooting steps (for Designjet 800 and Designjet 800ps)

If any of the troubleshooting steps listed below solve the problem, attempt to verify printer functionality (instructions below). If functionality is verified, no additional parts should be replaced.

Turn the printer on and listen for internal printer noise (fans, carriage movement, etc.).
If internal printer noise is observed after being turned on, continue with Step 9.
If no noise is observed, continue with Step 4.
Disconnect the printer from any surge protectors, universal power supplies or other similar devices and connect the power cord directly to a wall outlet.
Turn the printer on; if problems persist, try another wall outlet.
If unsuccessful, try another power cord (if available).
If the printer does not respond, replace the Power Supply (refer to pg. 8-27 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below). Continue with the remaining steps if the problem persists.
Follow the instructions below to increase the contrast settings:
1. Unload any media. Turn the printer off then on (allow 50 seconds for printer initialize).
2. Following initialization (when printer is quiet), press the Down Arrow one time, then press Enter.
3. Press the Down Arrow seven times (for Designjet 800), or eight times (for Designjet 800ps), and then press Enter.
4. Press the Down Arrow two times, then press Enter.
5. Press the Up Arrow ten times, then press Enter.
6. Press the Back key until Paper Menu appears.
If the printer display is now visible, the contrast settings were turned down. Verify printer functionality as described below.
If the display does not become visible, replace the Front Panel (refer to pg. 8-9 of the 500/800 Series Service Manual).
Following replacement, turn the printer on and attempt to verify functionality (instructions below).
If the problem persists, replace the Electronics module (refer to pg. 8-24 of the 500/800 Series Service Manual).
Verify functionality as described below.

Verifying printer functionality

Turn the printer on.
Allow initialization to complete.
Load media into the printer.
From the main front panel menu, select Ink and press Enter.
Select Troubleshooting and press Enter.
Follow the instructions on the front panel.
Following a successful troubleshooting plot, printer functionality has been verified.

	Parts required (part numbers are subject to change)
	Troubleshooting steps (for Designjet 500 without an HP-GL/2 Accessory Card)
	Troubleshooting steps (for Designjet 500 with an HP-GL/2 Accessory Card)
	Troubleshooting steps (for Designjet 800 and Designjet 800ps)
	Verifying printer functionality