Dell P2725H Service Manual

General Safety Instructions

Use the following safety guidelines to help ensure your own personal safety and to help protect your equipment and working environment from potential damage.

NOTE: In this section, equipment refers to monitors.

IMPORTANT NOTICE FOR USE IN HEALTHCARE ENVIRONMENTS:

Dell products are not medical devices and are not listed under UL or IEC 60601 (or equivalent). As a result, they must not be used within 6 feet of a patient or in a manner that directly or indirectly contacts a patient.

1.1 SAFETY: General Safety

WARNING: To prevent the spread of fire, keep candles or other open flames away from this product at all times.

When setting up the equipment for use:

• Place the equipment on a hard, level surface. Leave 10.2 cm (4 in) minimum of clearance on all vented sides of the computer to permit the airflow required for proper ventilation.
• Restricting airflow can damage the computer or cause a fire.
• Do not stack equipment or place equipment so close together that it is subject to recalculated or preheated air.
• NOTE: Review the weight limits referenced in your computer documentation before placing a monitor or other devices on top of your computer.
• Ensure that nothing rests on your equipment's cables and that the cables are not located where they can be stepped on or tripped over.
• Ensure that all cables are connected to the appropriate connectors. Some connectors have a similar appearance and may be easily confused (for example, do not plug a telephone cable into the network connector).
• Do not place your equipment in a closed-in wall unit or on a bed, sofa, or rug.
• Keep your device away from radiators and heat sources.
• Keep your equipment away from extremely hot or cold temperatures to ensure that it is used within the specified operating range.
• Do not push any objects into the air vents or openings of your equipment. Doing so can cause fire or electric shock by shorting out interior components.
• Avoid placing loose papers underneath your device. Do not place your device in a closed-in wall unit, or on a soft, fabric surface such as a bed, sofa, carpet, or a rug.

When operating your equipment:

• Do not use your equipment in a wet environment, for example, near a bath tub, sink, or swimming pool or in a wet basement.
• Do not use AC powered equipment during an electrical storm. Battery powered devices may be used if all cables have been disconnected.
• Do not spill food or liquids on your equipment.
• Before you clean your equipment, disconnect it from the electrical outlet. Clean your device with a soft cloth dampened with water. Do not use liquids or aerosol cleaners, which may contain flammable substances.
• Clean the monitor display with a soft, clean cloth and water. Apply the water to the cloth, then stroke the cloth across the display in one direction, moving from the top of the display to the bottom. Remove moisture from the display quickly and keep the display dry.
• Long-term exposure to moisture can damage the display. Do not use a commercial window cleaner to clean your display.
• If your equipment does not operate normally - in particular, if there are any unusual sounds or smells coming from it - unplug it immediately and contact an authorized dealer or service center.

Protecting Against Electrostatic Discharge

Electrostatic discharge (ESD) events can harm electronic components inside your equipment. Under certain conditions, ESD may build up on your body or an object, such as a peripheral, and then discharge into another object, such as your computer. To prevent ESD damage, you should discharge static electricity from your body before you interact with any of your equipment's internal electronic components, such as a memory module. You can protect against ESD by touching a metal grounded object (such as an unpainted metal surface on your computer's I/O panel) before you interact with anything electronic. When connecting a peripheral (including handheld digital assistants) to your equipment, you should always ground both yourself and the peripheral before connecting it. In addition, as you work inside the equipment, periodically discharge any static charge your body may have accumulated.

You can also take the following steps to prevent damage from electrostatic discharge:

• When unpacking a static-sensitive component from its shipping carton, do not remove the component from the antistatic packing material until you are ready to install the component.
• Just before un wrapping the antistatic package, be sure to discharge static electricity from your body.
• When transporting a sensitive component, first place it in an antistatic container or packaging.
• Handle all electrostatic sensitive components in a static-safe area. If possible, use antistatic floor pads and work bench pads.

1.2 SAFETY: General Power Safety

Observe the following guidelines when connecting your equipment to a power source:

• Check the voltage rating before you connect the equipment to an electrical outlet to ensure that the required voltage and frequency match the available power source.
• Do not plug the equipment power cables into an electrical outlet if the power cable is damaged.
• Norway and Sweden: If this product is provided with a 3-prong power cable, connect the power cable to a grounded electrical outlet only.
• If you use an extension power cable, ensure that the total ampere rating of the products plugged in to the extension power cable does not exceed the ampere rating of the extension cable.
• If you must use an extension cable or power strip, ensure the extension cable or power strip is connected to a wall power outlet and not to another extension cable or power strip. The extension cable or power strip must be designed for grounded plugs and plugged into a grounded wall outlet.
• If you are using a multiple-outlet power strip, use caution when plugging the power cable into the power strip. Some power strips may allow you to insert a plug incorrectly. Incorrect insertion of the power plug could result in permanent damage to your equipment, as well as risk of electric shock and/or fire. Ensure that the ground prong of the power plug is inserted into the mating ground contact of the power strip.
• Be sure to grasp the plug, not the cable, when disconnecting equipment from an electric socket.

If your equipment uses an AC adapter:

• Use only the Dell provided AC adapter approved for use with this device. Use of another AC adapter may cause a fire or explosion.
• NOTE: Refer to your system rating label for information on the proper adapter model approved for use with your device.
• Place the AC adapter in a ventilated area, such as a desk top or on the floor, when you use it to run the computer or to charge the battery. Do not cover the AC adapter with papers or other items that will reduce cooling; also, do not use the AC adapter inside a carrying case.
• The AC adapter may become hot during normal operation of your computer. Use care when handling the adapter during or immediately after operation.
• It is recommended that you lay the adapter on the floor or desk so that the green light is visible. This will alert you if the adapter should accidentally go off due to external effects. If for any reason the green light goes off, disconnect the AC power cord from the wall for a period of ten seconds, and then reconnect the power cord.
• Japan Only: Use only the Dell-provided AC power cable with the AC adapter. Use of any other power cable may damage the device or AC adapter or may present risk of fire or electric shock.

Exploded View Diagram and Parts List

The following diagram illustrates the components of the monitor and provides a list of these parts.

Diagram Description: The diagram shows the monitor disassembled into its main components, including the panel, frame, various boards (USB, power, interface, control), shielding, covers, column, and base. Cables for power, DisplayPort, and USB are also shown.

NOTE: For replacement of power cord, connectivity cable and external power supply (if applicable), contact Dell:

1. Go to https://www.dell.com/support.
2. Verify your country or region in the Choose A Country/Region drop-down menu at the bottom-right corner of the page.
3. Click Contact Us next to the country dropdown.
4. Select the appropriate service or support link based on your need.
5. Choose the method of contacting Dell that is convenient for you.

Wiring Connectivity Diagram

The diagram illustrates the internal wiring connections within the monitor, showing the placement and routing of flexible flat cables (FFCs) and wires.

Diagram Description: The diagram shows the rear internal view of the monitor with labels pointing to FFC 1, FFC 2, Wire1, and FFC 3, indicating their positions and connections.

Connecting and Disconnecting Cables

WARNING: To change power cable/connectivity cable, switch off power before unplugging the cable and replugging in the required cable.

Connecting DisplayPort, USB 3.2 Upstream, and Power Cables

Description: This section shows how to connect the DisplayPort (DP to DP) cable, USB 3.2 upstream cable, and power cable. The diagram illustrates connecting the monitor's ports to the corresponding ports on a computer. The monitor ports shown are DisplayPort, USB-A, and the power connector. The computer ports shown are also DisplayPort, USB-A, and power input.

Connecting HDMI, USB 3.2 Upstream, and Power Cables

Description: This section illustrates connecting the HDMI cable (optional), USB 3.2 upstream cable, and power cable. Similar to the DisplayPort connection, it shows the monitor's HDMI, USB-A, and power ports connecting to the computer's HDMI, USB-A, and power input.

Connecting VGA, USB 3.2 Upstream, and Power Cables

Description: This section details the connection of the VGA cable (optional), USB 3.2 upstream cable, and power cable. The diagram shows the monitor's VGA, USB-A, and power ports connecting to the computer's VGA, USB-A, and power input.

Disassembly and Assembly Procedures

NOTE: These procedures are for EMEA only. Dell will deem warranty void if any disassembly is performed on the monitors.

5.1 Disassembly SOP (Standard Operating Procedure)

Preparation before disassembly:

1. Clean the room for work.
2. Identify the area for material.
3. Prepare the implement, equipment, materials: Working table, Philips-head screwdriver, Hex-head screwdriver, Gloves, Cleaning cloth, ESD protection.

Step S1: Turn off the monitor.

Step S2: Place the monitor on a soft cloth or cushion. Press and hold the stand release button at the back of the display. Lift the stand assembly up and away from the monitor.

Step S3: Unlock 4 screws on the "Rear Cover". (Screw Torque: 9±1 kgf)

Step S4: Use hands or a "Bar Scraper" to disassemble the "Rear Cover" from the "Middle Frame" according to the sequence shown in the picture.

Step S5: Pull out the "Control board FFC" from the "Interface board" and tear it off from the "Main Shielding" to take off the "Rear Cover".

Step S6: Unlock 3 screws to disassemble the "Control board" from the "Rear Cover". Tear off the "Control board FFC" from the "Rear Cover" and take off the "Control board" from the "Rear Cover".

Step S7: Disassemble the "Control board FFC" from the "Control board". (Screw Torque: 1.6-1.8 kgf)

Step S8: Tear off a black tape from the "USB board FFC" and "Panel". Disassemble the "USB board FFC" from the "USB board" and "Interface board". Unlock 1 screw on the "USB board". Disassemble the "USB board" from the "Middle Frame". (Screw Torque: 4.5±0.5 kgf)

Step S9: Tear off a gasket from the "USB Shielding" (see pink mark). Tear off a gasket from the "USB board" (see red mark).

Step S10: Disassemble the "USB board" from the "USB Shielding".

Step S11: Tear off a tape from the "Backlight wire". Unplug the "Backlight wire" from the "Power board" and "Panel".

Step S12: Tear off 2 conductive tapes from the "Main Shielding" and "Panel".

Step S13: Tear off a long tape from the "LVDS FFC". Disassemble the "LVDS FFC" from the "Panel". Take off the "Main Shielding" from the "Panel".

Step S14: Unlock 15 screws to disassemble the "Middle Frame" from the "Panel". Take off the "Middle Frame" from the "Panel". (Screw Torque: 4.5-5.0 kgf)

Step S15: Disassemble the "MYLAR" from the "Main Shielding".

Step S16: Unlock 2 hexagonal screws. (Screw Torque: 5.0±0.6 kgf)

Step S17: Unlock 5 PCBA screws. (Screw Torque: 9±1 kgf)

Step S18: Disassemble the "Interface board" and "Power board" from the "Main Shielding". Unplug all cables from the "Interface board".

5.2 Assembly SOP

Preparation before assembly:

1. Clean the room for work.
2. Identify the area for material.
3. Prepare the implement, equipment, materials: Working table, Philips-head screwdriver, Hex-head screwdriver, Gloves, Cleaning cloth, ESD protection.

Step S1: Assemble the "Power board" to the "Main Shielding".

Step S2: Insert the "LVDS FFC" into the "Interface board". Insert the "Power board wire" to the "Interface board".

Step S3: Assemble the "Interface board" to the "Main Shielding". Lock 5 PCBA screws. (Screw Torque: 9±1 kgf)

Step S4: Lock 2 hexagonal screws. (Screw Torque: 5.0±0.6 kgf)

Step S5: Assemble the "MYLAR" to the "Main Shielding".

Step S6: Assemble the "Middle Frame" with the "Panel". Lock 15 screws to fix the "Middle Frame" with the "Panel". (Screw Torque: 4.5-5.0 kgf)

Step S7: Insert the "LVDS FFC" to the "Panel". Attach a long acetate tape to fix the "LVDS FFC" on the "Panel". Place the "Main Shielding" on the "Panel".

Step S8: Attach 2 conductive tapes on the "Main Shielding" and "Panel".

Step S9: Insert the "Backlight wire" to the "Panel" and "Power Board". Attach a tape to fix the "Backlight wire" on the "Panel".

Step S10: Assemble the "USB board" with the "USB Shielding".

Step S11: Attach a gasket on the "USB board" (see red mark). Attach a gasket on the "USB Shielding" (see pink mark).

Step S12: Assemble the "USB board" with the "Middle Frame". Lock 1 screw to fix the "USB board" on the "Middle Frame". Insert the "USB board FFC" to the "USB board" and "Interface board". Attach a black tape to fix the "USB board FFC" on the "Panel". (Screw Torque: 4.5±0.5 kgf)

Step S13: Insert the "Control board FFC" to the "Control board".

Step S14: Assemble the "Control board" to the "Rear Cover". Lock 3 screws to fix the "Control board" on the "Rear Cover". (Screw Torque: 1.6-1.8 kgf)

Step S15: Insert the "Control board FFC" into the "Interface board" and paste it on the Main SHD.

Step S16: Assemble the "Rear Cover" with the "Middle Frame" according to the sequence shown in the picture. Lock 4 screws to fix the "Rear Cover". (Screw Torque: 9±1 kgf)

Step S17: To Assemble stand: Insert the stand base blocks fully into the stand slot. Lift the screw handle and turn the screw clockwise. After fully tightening the screw, fold the screw handle flat within the recess.

Step S18: Attach the stand assembly to the display. a. Fit the two tabs on the upper part of the stand to the groove on the back of the display. b. Press the stand down till it snaps into place.

Troubleshooting Instructions

WARNING: Before you begin any of the procedures in this section, follow the Safety instructions.

Self-test

Your monitor provides a self-test feature that allows you to check whether your monitor is functioning properly. If your monitor and computer are properly connected but the monitor screen remains dark, run the monitor self-test by performing the following steps:

1. Turn off both your computer and the monitor.
2. Unplug the video cable from the computer.
3. Turn on the monitor.

If the monitor cannot sense a video signal and is working correctly, the following message will appear:

Message Example: "No DP Cable. The display will go into Standby mode in 4 minutes. www.dell.com/support/P2X25H" or similar variations.

NOTE: The message may be slightly different according to the connected input signal.

NOTE: While in self-test mode, the power LED remains white.

Note: This message also appears during normal system operation if the video cable becomes disconnected or damaged.

Step 5: Turn off your monitor and reconnect the video cable; then turn on both your computer and the monitor.

If your monitor screen remains blank after you use the previous procedure, check your video controller and computer, because your monitor is functioning properly.

Built-in Diagnostics

Your monitor has a built-in diagnostic tool that helps you determine if the screen abnormality you are experiencing is an inherent problem with your monitor, or with your computer and video card.

To run the built-in diagnostics:

1. Ensure that the screen is clean (no dust particles on the surface of the screen).
2. Move or press the joystick to launch the Menu Launcher.
3. Move the joystick up to select the Menu icon and open the Main Menu.
4. Move the joystick to navigate and select Others and then Self-Diagnostic.
5. Press the joystick to initiate the built-in diagnostics. A gray screen is displayed.
6. Observe if the screen has any defects or abnormalities.
7. Toggle the joystick once again until a red screen is displayed.
8. Observe if the screen has any defects or abnormalities.
9. Repeat steps 7 and 8 until the screen displays green, blue, black, and white colors. Note any abnormalities or defects.

The test is complete when a text screen is displayed. To exit, toggle the joystick control again.

If you do not detect any screen abnormalities upon using the built-in diagnostic tool, the monitor is functioning properly. Check the video card and computer.

Common Problems

The following table contains general information about common monitor problems you might encounter and the possible solutions:

NOTE: Auto Adjust, Phase, and Pixel Clock are only available for VGA input source.

Product Specific Problems

Universal Serial Bus (USB) Specific Problems