User's Manual

Troubleshooting
1-11
HP DesignJets 500, 510 and 800 Series Printers Service Manual
Using the Power Switch LED to Troubleshoot
In certain circumstances the LED located in the power switch
(located on the left hand side of the Printer) can help to troubleshoot
the Printer. The LED can be OFF, ON or flashing and using different
combinations can indicate different problems.
NOTE You should only use the LED to troubleshoot when the Printer
does not Power up completely. The LED may flash in other
circumstances which are completely normal and this does not
mean that there is a problem with the Printer.
LED is OFF - This indicates that the Power Supply Unit is
completely dead. Try the following:
1 Check that power cord is connected correctly to the Printer and to
the Power Socket. Also make sure that you firmly press the Power
Switch to the ON position.
2 Replace the Power Supply Unit ⇒ Page 8-27.
LED is ON (all the time) - This indicates that the Main PCA is
completely dead. Replace the Electronics Module ⇒ Page 8-24.
LED is Flashing continuously - A problem has been detected with the
previous firmware upgrade. Try resending the firmware upgrade file.
LED Flashes twice every few seconds - The Printer cannot detect
LED OFF
LED ON