Service Source

General Information

Overview

The Apple Cinema HD Display 23" LCD (ADC) features a high-resolution display with advanced technology. The document provides general information, tools required for servicing, and safety precautions.

Front View Description

The front view shows the display panel itself. Key elements include the 'Launch Button', which brings up the Apple Display preferences window, and the 'Power On/Off Button' which controls the display's power state.

Rear View Description

The rear view illustrates the back of the display. It highlights the 'USB Ports' for connectivity and the 'ADC Connector' for data and power transmission.

Tools Required

The following tools are recommended for the take-apart procedures:

• Cotton gloves (Part No. 922-1592)
• Hex key set, metric
• Phillips #1 screwdriver
• Phillips #0 jeweler's screwdriver (for backlight bulb trays)
• Volt meter (for troubleshooting)
• Black stick (nylon probe tool 922-5065) or other ESD-safe, non-marring tool
• ESD wriststrap and mat

Before Working on the Display

Warning: There is a risk of electric shock, fire, or other hazard if the Inverter Board, ADC Cable, MLB to USB Socket Cable, and the LCD Display Module are not replaced with the correct Apple service part.

Warning: Unless otherwise instructed, disconnect the ADC connector from the computer to ensure the display is not receiving power during service to avoid the risk of electric shock, fire, or other hazard.

Important Notes:

• The display LCD and the case can scratch and retain fingerprints easily. Use clean soft cotton gloves.
• Rest LCD screen and case parts on a soft, clean surface.
• If available, use a protective film over the display to prevent scratches.
• Remove all jewelry that could scratch or damage the display or plastic housing.
• Do not press on the LCD display panel or its edges, as damage can result.
• Avoid high temperature, humidity, and direct sunlight.
• Follow ESD safe procedures, including using a grounded wrist strap, to avoid circuit damage.

Take Apart Procedures

3. HINGE & EMI SHIELD REMOVAL

Steps to remove the hinge and EMI shield:

1. Remove two aluminum shielding tape pieces (a), part of shield tape kit 076-0978.
2. Remove four hinge screws (b), typically 3.0 x 6.0 mm (Part No. 922-5603).
3. Remove the hinge.
4. Remove four shield screws (c), typically 3.5 x 5.5 mm, Yellow Color (Part No. 922-5604).
5. Remove the Metal Shield.

Diagram Description: Shows the rear of the display with screws labeled (a), (b), and (c) indicating removal points for shielding and hinge components.

4. MAIN ADC CABLE & USB CONNECTOR REMOVAL

Steps to remove the main ADC cable and USB connector:

1. Remove four screws (a) and (a)-1.
2. Disconnect J12, J702, and the TMDS connector.
3. Remove the main ADC cable.
4. Remove four screws (b) and (b)-1.
5. Disconnect the J11 connector.
6. Remove the USB connector.

Diagram Description: Illustrates the internal layout showing connections like TMDS, J12, J702, and J11, and the routing of cables. Screws (a), (a)-1, (b), (b)-1 are indicated for removal. Screw types are specified as 3.5 x 5.5 mm (Part No. 922-5604) and 3.0 x 6.0 mm (Part No. 922-5603).

5. MAIN BOARD & INVERTER BOARD REMOVAL

Steps to remove the main board and inverter board:

1. Disconnect connectors J703, J701, J705, J704.
2. Remove four screws (a).
3. Remove the main board.
4. Disconnect connectors CN1, CN2, CN3, CN4, CN5.
5. Remove screw (b).
6. Remove the inverter board.

Diagram Description: Shows the main board and inverter board with associated connectors (CN1-CN5, J701-J705) and screws (a), (b). Screws are specified as 3.0 x 4.0 mm (Part No. 922-5605).

6. DISPLAY PANEL & CHASSIS REMOVAL

Steps to remove the display panel and chassis:

1. Remove eight screws (a), typically 3.0 x 8.0 mm.
2. Remove the chassis with the display panel attached.

Diagram Description: Depicts the display panel and chassis assembly, indicating the eight screws (a) that secure it.

7. LCD DISPLAY REMOVAL

Steps to remove the LCD display:

1. Remove four screws (a), typically 3.0 x 18.0 mm (Part No. 922-5607).
2. Remove four screws (b), typically 3.0 x 4.0 mm (Part No. 922-5605).
3. Remove the LCD display.

Diagram Description: Shows the LCD display being separated from its mounting, with screws (a) and (b) indicated for removal.

8. BACKLIGHT REMOVAL

The display has two backlight bulb trays (upper and lower) which are not interchangeable. The backlight bulbs are delicate and require careful handling.

Warning: To avoid electric shock, fire, or other hazard, disconnect the ADC connector and both backlight wire connectors at the inverter board before proceeding.

1. Use a #0 jeweler's screwdriver to remove screw (a).
2. For the lower bulb, loosen side screws at triangles (b) as needed.
3. For the upper bulb, remove screws securing the cover plate, remove the plate, then loosen side screws at triangles (b) as needed.
4. Very carefully slide out the backlight bulb tray.

Important: The backlight bulbs are extremely fragile. Handle with care.

Diagram Description: Illustrates the backlight assembly, showing the cover plate and screws (a) and (b) for accessing and removing the backlight bulb trays.

9. TOUCH SWITCH REPLACEMENT

Steps to replace the touch switch:

1. Insert a black stick (Part No. 922-5065) into slots along the edge to pry off the inner bezel.
2. Remove the touch switch securing screw, then remove the touch switch (Part No. 922-5530).
3. Transfer the screw and rubber boot (Part No. 922-5541) to the new switch installation.

Diagram Description: Shows the location of the touch switch and its associated boot, with the black stick tool used for prying.

Troubleshooting

This section provides guidance for diagnosing and resolving common issues with the Apple Cinema HD Display 23" LCD (ADC).

How to Use the Symptom Charts

The Symptom Charts help diagnose specific symptoms. Cures are listed in order of likelihood. Try cures in the presented order and verify if the symptom persists. If a module was replaced, reinstall the original module before trying the next cure. Referring to the Block Diagram may be helpful.

Symptom: Blank Screen

A blank screen may indicate issues with the LCD panel, backlight bulbs, inverter, main board, or related cables/connectors.

1. Check the ADC cable; replace if damaged.
2. Inspect the ADC connector for bent pins. Straighten slightly bent pins; replace the cable if severely bent. Also, inspect the display port on the computer for broken pin dividers. If the computer's display port is damaged, it must be repaired before inserting the ADC connector.
3. Connect the display to a known-good computer with a known-good video card and ADC display port. Boot the computer and allow sufficient time for booting.
4. If the power button flashes (two short, one long, repeating pattern), it indicates a problem with the inverter, backlight bulbs, or related cables/connectors. Continue with troubleshooting steps.
5. To check if the LCD panel is working, press the launch button. If the screen is blank, you won't see the window. Shine a bright light (sunlight or high-intensity lamp) into the screen and check for a faint image of the Display Preferences window or desktop items.
• If desktop items are visible, the LCD panel is working; the issue may be with the inverter, backlight bulbs, or related cables/connectors.
• If no desktop items are visible, the issue may be with the LCD panel or the main board or related cables/connectors.
6. Important: Display lights generate significant heat and can damage the display. Be careful not to allow excessive heat near the screen or other parts, and do not let the light fixture touch the screen.
7. Warning: The inverter board generates high voltage when plugged in. Do not touch inverter board components, pins, or connectors while the display is connected to the computer.
8. Disconnect the display, open it, and check for secure connections at TMDS, Panel Power, J703, J701, J702, J12, CN1, CN2, CN3, CN4, and CN5. Refer to the Block Diagram for connector locations.
9. Connect the display to a known-good computer and boot it.
10. Verify voltage at J702 input: +24-28V. If not present, replace the ADC cable.
11. Verify voltage at J701, pin 10: +24-28V. If not present, replace the main board.
12. Verify voltage at J703, pin 11: +5V. If not present, replace the main board.
13. Verify voltage at J703, pin 6: +18V. If not present, replace the main board.

Symptom: Partially Dim Screen

This symptom may indicate a problem with the inverter or backlight bulbs (on the dim side) or related cables/connectors.

1. Connect the display to a known-good computer with a known-good video card and ADC display port, then boot the computer.
2. Observe the power button for a flashing pattern (two short flashes, then a long flash, repeating). This pattern may indicate trouble with the inverter, backlight bulbs, or related cables/connectors. Continue troubleshooting.
3. Warning: The inverter board generates high voltage. Do not touch its components, pins, or connectors when the display is connected to the computer.
4. Disconnect the display, open it, and check connections at CN1, CN2, CN3, CN4, and CN5.
5. Important: Backlight bulbs are delicate. To diagnose between backlight bulbs and the inverter, disconnect the two CN connectors to the backlight bulbs on the dim side. Connect these to a known good backlight bulb tray (you can test by swapping the trays if they are identical, but they are not interchangeable). Connect the display to a known-good computer. If one or more bulbs do not light, replace the inverter. If bulbs light correctly, the original backlight bulb tray is faulty and needs replacement.
6. Note: The top and bottom backlight bulb trays are specific and not interchangeable.

Symptom: USB Device Not Working

1. Check the ADC connector for bent pins. Straighten slightly bent pins; replace the cable if severely bent. Inspect the computer's display port for broken pin dividers. Repair the port if damaged before inserting the ADC connector.
2. Connect the display to a known-good computer with a known-good ADC display port. Boot the computer. Connect a known-good USB device to one of the display's USB ports and check Apple System Profiler to see if it is recognized. Check both USB ports.
3. Note: Pressing Command+R refreshes the Apple System Profiler list when USB devices are changed.
4. If the device is recognized, the customer's USB device may be the issue.
5. If not recognized, check the J11 and J12 USB connections and cables. If the problem persists, replace the main board.

Diagram Description: An Apple System Profiler screenshot showing USB information, including USB Bus 0 and USB Bus 1, with devices like 'Studio Display' and 'Apple Optical USB Mouse' listed.

Symptom: Touch Switch Not Working

1. Check J705 or J704 connections and cables.
2. Check J12 connection and cable.
3. Replace the touch switch.
4. Replace the main board.

Symptom: Pixels Not Properly Lit

When displaying a single color, the LCD panel may show one or more pixels that are not properly lit. This is due to active-matrix LCD technology where each pixel has three subpixels (red, green, blue), each controlled by a transistor. Occasionally, a transistor may fail, resulting in a subpixel being stuck on (bright) or off (dark).

A certain number of subpixel anomalies is considered acceptable, as rejecting all but perfect panels would significantly increase retail prices. These factors apply to all LCD manufacturers.

To determine if the display has an acceptable number of pixel anomalies:

1. Set the display image to a solid color: all-white, all-red, all-green, or all-blue.
2. Note: Knowledge Base article 112125, 'Service Diagnostics Matrix', provides the LCD Tester Diagnostic Utility for generating these patterns.
3. Using a jeweler's loupe, pocket microscope, or other magnifying device, identify and count each subpixel anomaly:
• Bright subpixel anomaly: subpixel always on.
• Dark subpixel anomaly: subpixel always off.
4. Important: Check the number of subpixel anomalies against the following chart:

4. If the number of subpixel anomalies exceeds the acceptable number listed in the chart, replace the display panel.
5. If the number of subpixel anomalies is acceptable, explain to the customer that the pixel anomalies are within specifications and no repair is necessary.

Important: Do not release the specifications to customers. Inform them that a certain number of subpixel anomalies is considered acceptable, and these factors apply to all manufacturers using LCD technology.

Views and Parts

Exploded View Parts List

Exploded View Description

The exploded view diagram visually breaks down the display into its constituent parts, numbered according to the parts list. It shows how components like the rear cover, shields, hinge assembly, main board, inverter board, LCD panel, and bezels fit together. The diagram illustrates the physical arrangement and assembly sequence of these parts.

Diagrams

Wiring Diagram Description

The wiring diagram illustrates the internal electrical connections of the Apple Cinema HD Display 23" LCD. It shows how the Main Board (Part No. 661-2867) connects to various components via cables and connectors, including the Inverter Board (Part No. 661-2866), backlight bulbs (upper and lower), ADC cable (Part No. 922-5585), USB socket cable (Part No. 922-5584), and launch switch cable (Part No. 922-5588). Key connectors like CN1-CN5 and J701-J705 are identified.

Block Diagram Description

The block diagram provides a simplified overview of the display's internal architecture. It shows the functional relationships between major components such as the Inverter Board, Main Board, Backlight Bulbs (Upper and Lower), LCD Panel, and USB Ports. It illustrates signal paths like TMDS and LCD Panel Power, and connections to the Power Switch and Launch Switch via the Main Board.