¶ AP Board
The full name of the AP Board is Application Processor Main Board. It is a circuit board in the printer that handles information interaction. It provides the printer with an independent operating environment and supports all system functions required by printer applications, including memory management, system firmware, graphics processing, and multimedia decoding.
The spare parts of the AP Board include the following:
- AP Board * 1
- BT3x5 Screws - Used for fixing the AP Board * 4
¶ When to Replace
You need to contact Bambu Lab Technical Support to confirm whether the problem occurring with the printer is caused by the AP Board.
Notes:
- For a machine with a replaced AP Board, skip the machine binding step when turning it on for the first time.
The new SN (Serial Number) is not activated, so the binding operation cannot be performed. Binding can only be completed after the SN is activated.
- After confirming the replacement is completed, you also need to replace the SN. Please contact Bambu Lab Technical Support and provide both the new and old SNs to complete the SN replacement. For how to obtain the SNs of the old and new AP Boards, refer to this article: How to Find the Serial Number and Activate a New Serial Number. It is recommended to take a photo of the AP Board's SN to save it before replacing the AP Board.
¶ Safety Warning
It's crucial to power off the printer before conducting any maintenance work, including work on the printer's electronics and tool head wires. Performing tasks with the printer on can result in a short circuit, leading to electronic damage and safety hazards.
During maintenance or troubleshooting, you may need to disassemble parts, including the hotend. This exposes wires and electrical components that could short circuit if they contact each other, other metal, or electronic components while the printer is still on. This can result in damage to the printer's electronics and additional issues.
Therefore, it's crucial to turn off the printer and disconnect it from the power source before conducting any maintenance. This prevents short circuits or damage to the printer's electronics, ensuring safe and effective maintenance. For any concerns or questions about following this guide, open a new ticket in our Support Page and we will do our best to respond promptly and provide the assistance you need.
¶ Removing the AP Board
¶ Step 1: Turn Off the Power
Turn off the printer power, unplug the power cable, and remove the top glass cover.
¶ Step 2: Remove the AP Board Cover
- Use an H2.0 hex key wrench to remove 1 fixing screw (BT2.6x8) and open the AP Board Cover;
- If you find it difficult to disassemble and assemble the AP Board Cover, you can refer to the relevant video steps in this wiki for operation (Click here to jump).
 |
 |
- Remove the AP Board Cover from the side near the front door.
¶ Step 3: Disconnect the Cables
Unplug plugs 1-10 on the AP Board one by one.
 |
 |
- Screen Connector Cable
- USB Port Board
- Left LED Light Cable (Red Plug)
- Right LED Light Cable (Blue Plug)
- MC-AP Cable (Communication)
- MC-AP Cable (Power Supply)
- TH Power Supply Cable (Transferred via AP Board)
- USB-C Cable
- Live View Camera Cable
A ground cable is connected to the screw at the bottom left corner.
Suggestions for Unplugging Plugs:
- For FPC cable plugs like #1 and #9, you need to first flip open the buckle, then pull out the FPC cable. Refer to the figure below: flip open the buckle first, then pull out the cable.
- When unplugging the cable plugs #2, #3, #4, and #5, press to unlock before pulling out the plugs. In addition, plug #2 is reinforced with electronic silicone; before unplugging, you can use tools such as tweezers to scrape off the silicone. This silicone is mainly used for reinforcement to prevent loosening during transportation. If there is no abnormality in USB flash drive reading and writing after reconnecting the plug later, it is not necessary to reapply the silicone.
- Before pulling out the #8 USB-C Cable, you need to first unscrew the screw of the cable organizer buckle, then pull the USB-C cable out of the buckle near the AP Board.
 |
 |
You can leave the WiFi antenna plug disconnected for now; after unscrewing the screws and removing the board, then disconnect the plug.
¶ Step 4: Remove the AP Board and Dismantle the WiFi Antenna Base
Use an H2.0 hex key wrench to unscrew 4 fixing screws (BT3×5), then remove the AP Board and disconnect the WiFi antenna plug.
A ground wire is connected to the fixing screw at the bottom left corner of the AP Board. You only need to unscrew the 4 screws on the AP Board end (marked with red circles); the screws connected to the printer frame (marked with green circles) can remain in place.
¶ Installing the AP Board
¶ Step 1: Connect the WiFi Antenna Plug and Reinstall the AP Board
According to the diagram below, align the positions and press to connect the WiFi antenna plug.
Align the AP Board with the screw holes on the upper frame. Note to organize the cables and avoid the WiFi antenna to prevent pressing the cables.
Use an H2.0 hex key wrench to tighten 4 fixing screws (BT3x5). There is a ground wire at the fixing screw at the bottom left corner of the AP Board. When installing the fixing screw at the bottom left corner of the AP Board, you need to lock the ground wire and the AP Board together.
¶ Step 2: Connect the Cables
Connect the plugs on the AP Board.
- Screen Connector Cable
- USB Port Board
- Left LED Light Cable (Red Plug)
- Right LED Light Cable (Blue Plug)
- MC-AP Cable (Communication)
- MC-AP Cable (Power Supply)
- TH Power Supply Cable (Transferred via AP Board)
- USB-C Cable
- Live View Camera Cable
A ground cable is connected to the screw at the bottom left corner.
Requirements for Plugging in Plugs:
- When inserting the USB-C Cable (#8), ensure the side with the "A" marking faces the inside of the printer chamber. After inserting the plug in place, organize the cable (this plug is relatively tight and requires a little force to push in; be careful not to loosen the plug when organizing the cable).
Screw in the screw for the USB-C Cable organizer buckle.
- For the Screen Connector Cable (#1) and Live View Camera Cable (#9), the small tabs on both sides of the cables need to be inserted into the sockets. For #1 and #9, the side with the "AP" marking should face the inside of the printer chamber. After closing the buckle, the buckle should be flat without warping.
- For #2, #3, #4, #5, #6, and #7, insert them according to the direction of the buckle to ensure the plugs are connected in place. If there is too much residual silicone on #2, you can first use tweezers to remove some silicone to ensure the plug is inserted smoothly in place.
¶ Step 3: Reinstall the AP Board Cover
Note: Before installing the AP Board Cover, check whether the cables block the PTFE tube to avoid affecting the subsequent installation of the PTFE tube.
First, fasten the AP Board Cover back from the side near the printer's rear panel. Press both positions indicated by the arrows into place: the right side should be flush with the buffer, and the bottom should be flush with the cable protection cover. Then use an H2.0 hex key wrench to tighten 1 fixing screw (BT2.6x8).
 |
 |
¶ How to Verify Successful Installation
Connect the power cable and turn on the power. Initiate a print job and check for any errors.
If errors occur, check whether all cables on the AP Board are connected correctly, then try again. If the problem persists, contact Bambu Lab Technical Support for further assistance.
¶ Required Tools and Materials
- New AP Board
- H2.0 Hex Key Wrench
Specifications and Quantity of Screws Involved in Replacing the H2D AP Board (It is recommended to keep the removed screws properly to avoid loss):
| Screw Specification | Screw Image | Purpose | Position Diagram | Quantity of Screws | |
|---|---|---|---|---|---|
| BT2.6x8 | Used for fixing the AP Board Cover |  |
1 | ||
| BT3x5 | Used for fixing the AP Board |  |
4 | ||
| BT3x5 | Used for fixing the USB-C Cable Organizer |  |
1 |
¶ End Notes
We hope the detailed guide provided has been helpful and informative.
If this guide does not solve your problem, please submit a technical ticket, we will answer your questions and provide assistance.
If you have any suggestions or feedback on this Wiki, please leave a message in the comment area. Thank you for your support and attention!