Apple AudioVision 14 Display Troubleshooting Guide

Exploded view with Apple part numbers (Apple Service Source)

Fault-finding for the Apple AudioVision 14 Display, from Apple's Service Source. Apple lists cures in order of likelihood; refit the original module before moving to the next cure if a replacement did not help. The hardware cures name only two modules, the main board and the CRT, plus the audio parts.

The CRT keeps a charge after switch-off. Follow the CRT Discharge Procedure before working inside, and do not wear a grounding wrist strap until the CRT has been discharged.

Picture faults

No raster, geometry and synchronisation (Service Source, Symptom Charts pp. 2-7)

Symptom	Cures, in Apple's order
No raster, LED off	Check the video cable is connected. Check the power cable and power switch. Check all connections on the main board. Replace a blown fuse. Replace the main board
No raster, LED on, CRT heater glowing	Check the video cable. Adjust contrast and brightness. Check the computer's video with a known-good monitor. Check all main board connections, making sure the video connector is secure and its wires are inside the plastic connector. Do the video adjustments. Replace the main board. Replace the CRT
Raster too short, tall, narrow or wide	Adjust the size controls. Replace the main board
Raster not centred	Move the display away from other monitors, fluorescent lights and electrical equipment. Adjust the centring controls. Replace the main board
Horizontal or vertical linearity bad	Replace the main board
Abnormal or distorted raster	Move the display. Do the geometry adjustments. Replace the main board. Replace the CRT (rarely needed)
Whole raster tilted	Move the display. Do the geometry adjustments, then the geometric distortion adjustments. Replace the main board
Picture breaks into diagonal lines, rolls vertically, or breaks and rolls horizontally	Check the computer's video with a known-good monitor. Replace the main board
Black raster with a single vertical or horizontal line	Replace the main board. Replace the CRT

Video (Service Source, Symptom Charts pp. 8-9)

Symptom	Cures, in Apple's order
Picture too dark, too bright or washed out	Adjust contrast and brightness. Check the video with a known-good monitor. Do the video adjustments. Replace the main board. Replace the CRT (rarely needed)
Out of focus	Do the focus adjustment. Replace the main board. Turn the focus controls to their limits: if one part of the screen stays out of focus, replace the CRT
Predominant colour tint	Check the video card. Do the video adjustments. Replace the main board. Replace the CRT if a red, green or blue tint cannot be removed
Out of convergence	Check the video with a known-good monitor. Do the convergence adjustments. Replace the main board. Replace the CRT

The adjustments are on the general maintenance page.

Sound

Apple's audio chart deals only with settings; it lists no hardware cure.

Audio (Service Source, Symptom Charts p. 10)

Symptom	Check
Sound from only one speaker	A sound output option may be set to stereo on a computer with mono output only
Built-in microphone does not record	Press the microphone button on the keypad (the microphone LED lights when it is on). Make sure the display is selected as the sound input and playback source
No sound or volume too low	Check external sound sources are connected to the display's sound-out port. Press the volume key. Turn mute off. Turn the microphone off

If the settings are right and a speaker is still silent, the speakers (922-0387), the audio enclosure with its sound board (922-0386) and the microphone (922-0389) are separate service parts.

Miscellaneous

Miscellaneous (Service Source, Symptom Charts pp. 11-13)

Symptom	Cures, in Apple's order
Picture jitters or flashes	Move the display away from other monitors, fluorescent lights and electrical equipment. Check the ground cables. Replace the main board
Shuts down intermittently; flashing or wavy screen; high-pitched noise; does not degauss	Replace the main board
Black spots (burnt phosphor)	Replace the CRT
ADB devices do not work or work erratically	Replace the keyboard cable, keyboard, mouse or other ADB device
A Logitech mouse moves nothing but the keyboard works	Some Logitech mice are incompatible with this display; the display is not at fault
Thin horizontal line about a third of the way up	Not a fault: the support wire of the Trinitron aperture grille on displays smaller than 15 in. It cannot be adjusted out or removed by replacing modules

Fuse

The mains fuse is on the main board: Apple part 922-0502, 4.0 A, 250 V. Remove the rear cover, discharge the CRT and remove the anode cap, then lever the fuse out with a small screwdriver. Apple's specification says it should be replaced with the same type by a qualified technician.

Removing the main board

The main board comes out after the audio enclosure and the video cable. Apple's order:

1. Remove the rear cover, discharge the CRT and remove the anode cap.
2. Cut the tie wrap on the yoke and ground cables, disconnect the two ground cables from the degauss panels and the four-wire CRT cable from BD1, and pull the video board assembly straight off the CRT neck: twisting or bending it can crack the neck.
3. Disconnect the degauss cable from BP2. Remove the four self-threading T-15 screws holding the base assembly to the bezel and lift the CRT assembly off the base onto a pad, minding the LED and microphone cables.
4. Release the cables from the B5 audio board (microphone at B5, front panel at B3, video at B4 and B10, four-wire cable at B8) and the audio ground cables from HP5 and HP6 on the main board. Loosen and pull out the two screws holding the base to the audio enclosure and slide the enclosure out.
5. Remove the screw holding the video cable to the EMI shield, unplug the cable from BV1 and lift out the strain relief plate.
6. Remove the two main board mounting screws, unplug BP3 and BP4 (on/off switch), BP5 and BV4 (audio), release the rear and then the front latches, and slide the board back off its mounting tabs.

After a new main board is fitted, Apple calls for the video (cutoff) adjustment.

Related pages

• Apple AudioVision 14 Display
• Apple AudioVision 14 Display General Maintenance
• Apple AudioVision 14 Display Service Source
• CRT Discharge Procedure