Troubleshooting CRT monitor issues

Resolving The Problem

1. To begin troubleshooting, check the following top issues. If your issue is listed, select the link, otherwise proceed to step 2.
   

   	Monitor setup - controls and degaussing
   	Caring for your monitor
   	No picture (screen is blank)
   	Picture is scrambled
   	Color is not uniform
   	Unable to adjust the monitor with the buttons on the front panel
   	Screen image is not centered or sized properly
   	Edges of the image are curved
   	White lines show red or blue shadows at edges
   	Picture is fuzzy
   	Picture bounces or has wavy oscillations
   	Picture is flickering
   	Picture appears to be ghosting
   	Wavy or elliptical (moire) pattern is visible
   	COLOR RETURN function does not operate
   	Two fine horizontal lines (wires) are visible
   	Hum is heard right after the power is turned on

   
   
2. Check our video troubleshooting document.
   
   
3. If these steps have not solved your problem:
   Refer to your system's Hardware Maintenance Manual, or refer to "Need more help?"
   
   

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Symptom	Perform the following steps to fix the problem
indicator is not lit	Check that the power cord is properly connected. Check that the (power) switch is in the "on" position.
"NO INPUT SIGNAL" message appears on the screen, or if the (power) indicator is either orange or alternating between green and orange	Check that the input switch setting is correct. Check that the video input connector's pins are not bent or pushed in. Check to see if the computer is in power saving mode. Try pressing any key on the computer keyboard or moving the mouse. Check that the computer's power is "on." Check that the video frequency range is within that specified for the monitor (Horizontal: 30-121 kHz, Vertical: 48-160 Hz) Check that the graphic board is completely seated in the proper bus slot.
"NO INPUT SIGNAL" and "CHECK SIGNAL CABLE" messages appear on the screen, or if the (power) indicator is either orange or alternating between green and orange	Check that the video signal cable is properly connected and all plugs are firmly seated in their sockets. Ensure that no pins are bent or pushed in the video input connector. Check that the input switch setting is correct. Check that the graphic board is completely seated in the proper bus slot.
"OUT OF SCAN RANGE" message appears on the screen	Check that the video frequency range is within that specified for the monitor (Horizontal: 30-121 kHz, Vertical: 48-160 Hz).
No message is displayed and the indicator is green or flashing orange	Refer to "Self-diagnosis function".

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1. Check your graphics board manual for the proper monitor setting.
2. Check the user's guide that comes with your monitorl and confirm that the graphics mode and the frequency you are trying to operate at is supported. Even if the frequency is within the proper range, some graphic boards may have a sync pulse that is too narrow for the monitor to sync correctly.
   

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1. Degauss the monitor. If you place equipment which generates a magnetic field, such as a loudspeaker, near the monitor, or you change the direction of the monitor, color may lose uniformity. The degauss function demagnetizes the metal frame of the CRT to obtain a neutral field for the uniform color reproduction. If a second degauss cycle is needed, allow a minimum interval of 20 minutes for the best result.
2. Adjust the landing.
   

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1. Press the button to automatically size or center the picture.
2. Adjust the size or centering.
   
   Note: Some video modes do not fill the screen to the edges. This problem tends to occur with certain graphic boards.

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Adjust the geometry.

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Adjust the convergence.

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1. Adjust the contrast and brightness.
2. Degauss the monitor.
   If you place equipment which generates a magnetic field, such as a loudspeaker, near the monitor, or you change the direction of the monitor, color may lose uniformity. The degauss function demagnetizes the metal frame of the CRT to obtain a neutral field for uniform color reproduction. If a second degauss cycle is needed, allow a minimum interval of 20 minutes for the best result.
3. If red or blue shadows appear along the edges of images, adjust the convergence.
4. If CANCEL MOIRE is ON, the picture may become fuzzy. Decrease the moire cancellation effect or set CANCEL MOIRE to OFF.

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1. Isolate and eliminate any potential sources of electric or magnetic fields. Common causes for this symptom are electric fans, fluorescent lighting, or laser printers.
2. If you have another monitor close to this monitor, increase the distance between them to reduce the interference.
3. Try plugging the monitor into a different AC outlet, preferably on a different circuit.
4. Try the monitor on a different computer in a different room.

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Set the refresh rate on the computer to obtain the best possible picture by referring to your computer's manual.

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Eliminate the use of video cable extensions and/or video switch boxes if this symptom occurs. Excessive cable length or a weak connection can produce this symptom.

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1. Set CANCEL MOIRE to ON and adjust the degree of moire cancellation until the moire is at a minimum.
2. Due to the relationship between resolution, monitor dot pitch and the pitch of some image patterns, certain screen backgrounds sometimes show moire. Change your desktop pattern.
   

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1. The monitor must be in normal operation mode (green power indicator on) for at least 30 minutes (for more information review using the COLOR RETURN).
2. Adjust the computer's power saving settings to keep the monitor in normal operation mode for more than 30 minutes.
3. The monitor may gradually lose its ability to perform this function due to the natural aging of the picture tube.
   

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These wires stabilize the vertically striped aperture grille. This aperture grille allows more light to pass through to the screen giving the Trinitron CRT more color and brightness. When viewing a white background, very thin horizontal lines may be visible on the screen as shown below. These lines are the shadows of the damper wires and are characteristic of CRTs that use aperture grilles. The wires are attached to the aperture grille on the inside of the Trinitron tube and prevent the vibration of the aperture grille.

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When the power is turned on, the auto-degauss cycle is activated. While the auto-degauss cycle is activated, a hum may be heard. The same hum is heard when the monitor is manually degaussed. This is not a malfunction.

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