ACER Monitor KA242Y Lifecycle Extension Guide

Important Safety Notice

Product Announcement: This product is certified to meet RoHS Directive and Lead-Free production definition. Using approved critical components only is recommended when replacing defective parts. The vendor assumes no liability, express or implied, arising out of any unauthorized modification of design or replacement of non-RoHS parts. Service providers assume all liability.

Qualified Repairability: Proper service and repair are crucial for the safe, reliable operation of all product series. Service providers recommended by the vendor should be aware of the notices listed in this service manual to minimize the risk of personal injury during service procedures. Furthermore, improper repairing methods may damage equipment or products. It is recommended that service engineers possess repairing knowledge, experience, and appropriate product training for new models before performing service procedures.

NOTICE:

• [!] To avoid electrical shocks, the product should be connected to an authorized power cord, and the master power switch turned off each time before removing the AC power cord.

• [!] Keep the product away from water or exposure to extremely high humidity environments.

• [!] To ensure the continued reliability of this product, use only original manufacturer's specified parts.

• [!] To ensure safe repairing behavior, place the replaced part on the component side of the PWBA, not the solder side.

• [!] To ensure the use of a proper screwdriver, follow the torque and force listed in the assembly and disassembly procedures to screw and unscrew screws.

• [!] Use Lead-Free solder to properly mount the parts.

• [!] The fusion point of Lead-Free solder requested is 220°C.

1. Exploded Diagram

The exploded diagram visually represents the internal components of the ACER Monitor KA242Y. It details the arrangement of parts and provides a reference list for identification.

Component List:

Note: The information contained herein is the exclusive property of Lehui and prior written permission of Lehui is required for reproduction.

2. Wiring Connectivity Diagram

The wiring diagram illustrates the internal connections within the monitor. It shows the Key board connected to the Main Board (MB) via FFC. The LVDS cable connects the display panel (LCM) to the Main Board. The Backlight is also connected to the Main Board via FFC. The Power Board connects to the Main Board via a wire.

3. Mechanical Instruction

Tools Required

The following tools are typically used for disassembly to a point where components and materials requiring selective treatment can be removed:

• Working table
• Screwdriver
• Knife
• Gloves
• Cleaning cloth
• ESD protection

4. Assembly and Disassembly Procedures

Disassembly Procedure

Step 1: Pull the base and neck assembly out.

Step 2: Unscrew four screws.

Step 3: Separate hooks between the MID_FRAME and Rear Cover (R/C).

Step 4: Pull up the Rear Cover and disconnect all connectors.

Step 5: Unscrew screws on the main shielding and disassemble the aluminum tape.

Step 6: Separate the speaker from the MID_FRAME and disconnect the LVDS & Backlight FFC from the LCM (Liquid Crystal Module).

Step 7: Unscrew two hex nuts and seven screws to remove the main board PCBA from the main shielding.

Step 8: Remove connector cables and separate the main board and power board. Separate mylar and shielding.

Step 9: Unscrew eleven screws and separate the MID FRAME and LCM.

Step 10: Separate the gasket and lens from the MID frame.

Step 11: Unscrew two screws and disassemble the key board from the rear cover. Separate the navigation key (navi key) and cable.

Step 12: Separate the wall-mount bracket (BKT) and display key from the rear cover.

Step 13: Unscrew the screw and separate the base & neck assembly.

Step 14: Remove six silicon rubbers and unscrew one screw.

Step 15: Unscrew two screws and Separate BKT from neck, unscrew three screws and separate hinge assy from neck.

Assembly Procedure

Step 1: Assemble the main board into the shielding, using screws to fix it. Mount the main board onto the LCM.

Step 2: Insert the 30-pin LVDS FFC to the LCM, then use acetate cloth tape to secure the FFC.

Step 3: Secure the shielding onto the panel with screws (indicated by red circles in the original image).

Step 4: Use aluminum (Al) tape to fix the shielding (indicated by blue circles in the original image).

Step 5: Insert the 6-pin backlight FFC to the panel and main board. Use acetate tape to secure it (indicated by red circles in the original image).

Step 6: Insert the 30-pin LVDS FFC to the main board. Use aluminum (Al) tape to fix it (indicated by blue circles in the original image).

Step 7: Apply yellow tape to secure the FFC (indicated by red circles in the original image).

Step 8: Assemble the middle frame with the LCM and fix it with screws (indicated by red circles in the original image).

Step 9: Secure the middle frame screws (indicated by red circles in the original image).

Step 10: For models with speakers, assemble the speaker onto the middle frame and connect the speaker cable to the main board. The red and white cable is on the left side, and the yellow and black cable is on the right side.

Step 11: Secure the speaker cable with acetate cloth tape (indicated by blue circles in the original image).

Step 12: Insert the key board FFC onto the main board. Note: 'other sku' and 'bi/bir' might refer to different versions or connector types.

Step 13: Assemble the rear cover and push around the edges to ensure a secure fit.

Step 14: Secure the rear cover with screws (indicated by red circles in the original image).

5. Troubleshooting

5.1 Test flow for abnormal machine:

This flowchart guides troubleshooting for abnormal machine behavior. The original document uses a visual flowchart; this text describes the decision paths.

• Start
• Decision: Check DC Power is 19V?
  • If No: Check AC power?
    • If AC power is available: Plug power cord into AC source.
    • If AC power is not available: Check adaptor.
• If Yes (DC Power is 19V):
  • Decision: Key's LED indicator is light or blink?
    • If light: BLACK screen but a little light?
      • If Yes: Re-insert 30pin LVDS cable between LCM and main board. Then, Decision: Still BLACK screen?
        • If Yes: Check Main board.
        • If No: END.
    • If blink: No input signal.
• Decision: Check Main board.
  • If No (Main board check fails): END.
  • If Yes (Main board check passes): Decision: 5VD_REG, 3V3D_REG and 1VD_REG on main board is normal?
    • If Yes: LCM broken. END.
    • If No: END.

5.2 Key debug flow:

• Start: Key Debug
• Action: Replace keyboard
• Decision: Key works?
  • If No: Check U12 works.
  • If Yes: END.

5.3 Panel debug flow:

• Start: LCM power Debug
• Action: Disconnect LVDS cable
• Decision: Check LCM power (R82) 5V ok?
  • If Yes: Replace panel. Then, Decision: Check set is ok?
    • If Yes: END.
    • If No: Check U12 works.
  • If No: Decision: Check Q1 pin2 is 5V?
    • If Yes: Decision: Check Q2 pin2 is high?(>2.4V)
      • If Yes: Replace Q1. END.
      • If No: Check U12 works.
    • If No: Check U12 works.

5.4 LED backlight debug flow:

• Start: LED driver Debug
• Decision: Check Net 19V_BLD is 19V?
  • If Yes: Decision: BU3 is damaged?
    • If Yes: Replace BU3.
    • If No: Decision: BD4 is damaged?
      • If Yes: Replace BD4.
      • If No: Decision: BR31 is open?
        • If Yes: Replace BR31.
        • If No: Decision: Check BU5 pin5 is high?
          • If Yes: Backlight on?
            • If Yes: END.
            • If No: Check U12 works.
          • If No: Open BR67. Then, Decision: Check NET BL_CTRL level is high?
            • If Yes: END.
            • If No: Check U12 works.
  • If No: Decision: FB36 is open?
    • If Yes: Replace FB36. Then, Decision: Check Net 19V_BLD is 19V? (Implies re-check or loop)
    • If No: Reassemble BR67. Then, Decision: Check Net 19V_BLD is 19V? (Implies re-check or loop)

Note: The flowcharts represent decision paths. 'Check U12 works' appears as a common fallback for several issues. 'Replace BU5' is also a potential action.

6. FRU (Field Replaceable Unit) List

The following table lists Field Replaceable Units (FRUs) for the ACER Monitor KA242Y.