LCD Monitor - How it Works and Troubleshooting Guide

How it Works

LCD monitors used by Haas operate in the same way that the LCD monitor of any PC or laptop operate. They are composed of two major parts: an LCD assembly, and a backlight. The backlight supplies white light for each one of the pixels in the LCD display.

On HAAS machines, the video system consists of a video circuit embedded in the main processor PCB. The circuit sends the video signals to a differential receiver which either stands alone or is embedded in the Serial Keyboard Interface (SKBIF) PCB in the front pendant. The receiver converts the video signal and sends it to the LCD monitor.

The back of a 10" LCD monitor equipped with an external differential receiver PCB [1].

The back of a 15" LCD monitor. This version does not require an external differential receiver PCB because it is built in to the SKBIF PCB [2].

Symptom Possible Cause Corrective Action Section
The LCD monitor shows flashing red, green, blue and black colors, or is solid white. Problem with the cables. Make sure the connections are fully seated. 1
The LCD monitor does not have video. Problem with the voltage to the backlight. Make sure the SKBIF PCB and differential receiver card have the correct voltage. 2
Problem with the backlight. Test the backlight. 3

Display off timer or screen saver delay are not resetting properly.

Reset settings 100 and 199. 4

Section 1

Symptom: The LCD monitor shows flashing red, green, blue and black colors, or is solid white.

Possible Cause: Problem with the cables.

Corrective Action:

10" LCD Monitors: Make sure that the video data cable from the J2 connector on the video PCB to the J3 connector on the differential receiver PCB is correctly connected.

15" LCD Monitors: Make sure that the video data cable from the J10 connector on the processor PCB to the J6 connector on the SKBIF PCB is correctly connected.

Make sure the video data cable from connector J16 on the SKBIF PCB or J4A on the differential receiver PCB to the LCD monitor is correctly connected.

Make sure the backlight cable from connector J13 on the SKBIF PCB or J2 on the differential receiver PCB is correctly connected.

Section 2

Symptom: The LCD monitor does not have video.

Possible Cause: Problem with the voltage to the backlight.

Corrective Action:

If there is voltage present, the LCD monitor has failed and must be replaced. If there is no voltage present or is low, check the power supply to the SKBIF PCB or differential receiver PCB.

10" LCD Monitors: Make sure the differential receiver PCB has 12 VDC. Measure the voltage at the P1 [1] connector. Measure the voltage across GND and +12 V.

 

 

 

15" LCD Monitors: Make sure the SKBIF PCB has 12 VDC. Measure the voltage across TP11 [1] and TP18 [2] test points.

Section 3

Symptom: The LCD monitor does not have video.

Possible Cause: Problem with the backlight.

Corrective Action:

With the machine power on, point a light to the LCD monitor. If you can see the information on the display, the backlight has failed. Replace the LCD monitor.

Section 4

Symptom: The LCD monitor does not have video.

Possible Cause: Display off timer or screen saver delay are not resetting properly.

Corrective Action:

Setting 199, Display off timer, or Setting 100 Screen saver delay, are not resetting properly. Change Settings 100 and 199 to 0.

If this resolves the symptom, contact your local HFO to update your machine software.

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.

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