HP Latex 300 series. Understanding Printer’s LED Language.

Digital printers are getting smart in many ways. They designed to minimize operator intervention in critical situations. Oftentimes digital printers can speak to us in a printer specific language expressed in term of blinking LEDs, beeps or error messages on front panel whenever there is issues on hardware level. Today I will be sharing my personal experience on troubleshooting electronic components of an HP Latex 360 model and Latex 300x series in general to identify failed part. The more we understand printers, the less money and valuable time required on getting a printer up and running again. Those who use DesignJets can also benefit from the article. Latex printer malfunction can be divided into four main categories: 

1. Continuable. (Software)
2. Non-continuable. (Hardware)
3. Warnings. (User Actions)
4. Alerts. (Settings).

We are going to focus on “Non-continuable” malfunction, specifically cases when the printer does not power on. Hardware failure beginning to reveal itself mostly during the printer initialization. It is highly recommended to run a test on failed part or assembly before even thinking about replacement. No replacement necessary if test passes. It is very rare that two or more components fails simultaneously. 

LED language

There are 7 main LEDs available on Latex printers to visually troubleshoot an electrical and circuit board in case printer does not powers on.

First LED located on Front Panel. 

Second, third and fourth (Power orange, Power Blue, Power Green) LEDs are located at the back of the printer, just above power switch.

Fifth, sixth and seventh (orange) LEDs located on Main Board, above USB port.

Once we understand LEDs, we can easily identify the source of hardware malfunction which prevents printer from normal boot and initialization. Once we know which part fails, we can go ahead and test that particular part from system menu. If test fails, then we for sure know which part needs to be replaced in order printer to boot up successfully.

Case 1

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- on,

Main Board LED 2 status -- blinking,

Main Board LED 3 status -- off.

Reason: Hard Drive boot sector error. Operating system could not be loaded.

Solution: Replace Hard Drive.

Case 2

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- off,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Reason: Mainboard is not receiving power from Power Supply Unit.

Solution: Turn off printer and wait 10 minutes till capacitors drained electricity then turn on printer again. If system is not booting up, replace Power Sypply Unit.

Case 3

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- on,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Reason: Mainboard BIOS failed to load. (BIOS is a firmware that sits inside Mainboard’s flash memory. It controls hardware initialization procedure. When printer’s power button pushed, it is the first application being executed and starts hardware initialization process).

Solution: Most definitely Mainboard needs to be replaced.

Case 4

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- blinking,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Reason: Mainboard BIOS loaded successfully but failed to detect Hard Drive. 

Solution: Reseat Hard Drive data cables. If problem remains, replace Hard Drive. 

Case 5

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- off,

power (Green) LED status -- off,

Main Board LED 1 status -- off,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Front Panel LED status -- off

Reason: There is no 220V current in outlet. 

Solution: Check your circuit breaker. 

Case 6

LED State:

power (Orange) LED status -- on,

power (Blue) LED status -- off,

power (Green) LED status -- off,

Main Board LED 1 status -- off,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Front Panel LED status -- off

Reason: Front panel (Screen) malfunction. 

Solution: Turn off printer using power switch at the back of the printer, wait 10 minutes till the capacitors discharge remaining current in the circuit boards then turn on printer. If nothing changes, replace the Front Panel.

Case 7

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- on,

Main Board LED 2 status -- on,

Main Board LED 3 status -- off.

Front Panel LED status -- off

Reason: Mainboard could not communicate with one of the sub boards plugged to him.

Solution: Reseat the following circuit boards plugged to Mainboard: 1. LAN board, 2. OMAS board, 3. Engine Board. If nothing changes, replace the Mainboard.

Case 8

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- on,

Main Board LED 2 status -- on,

Main Board LED 3 status -- on.

Front Panel LED status -- off

Reason: Front panel (Screen) malfunction.

Solution: Reseat Front Panel cable on Mainboard. If nothing changes, Front Panel needs to be replaced.

Case 9

LED State:

power (Orange) LED status -- off,

power (Blue) LED status -- on,

power (Green) LED status -- off,

Main Board LED 1 status -- blinking,

Main Board LED 2 status -- off,

Main Board LED 3 status -- off.

Front Panel LED status -- off

Reason: Mainboard BIOS unable to start and initialize printer components.

Solution: Replace Mainboard.