> ## Knowledge Base Index > Fetch the complete knowledge base index at: https://help.simplyprint.io/sitemap.xml > Use this file to discover available pages before exploring further. > Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash). # Why is my Bambu Lab printer offline? # Why is my Bambu Lab printer offline? This guide helps troubleshoot why your Bambu Lab printer shows offline in SimplyPrint. SimplyPrint connects to Bambu Lab printers through the **SimplyPrint Bambu Lab Client** - an application that runs on the device where you installed it during [initial setup](https://simplyprint.io/setup-guide#bambu:1) (your PC, a Raspberry Pi, or another always-on device). --- ## Start here: Where is the problem? ### Step 1: Is the SimplyPrint Bambu Lab Client running? Go to the device where you installed the client and open its web interface (usually `http://localhost:8000`). ![SimplyPrint Bambu Lab Client interface](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/bambu-lab-client-overview_1j8ytay.png) - **Can't access the client?** → [Client isn't running](#2-1-client-isnt-running) - **Client is running?** → Continue to Step 2 ### Step 2: What does the printer show in the client? Look at your printer's status badge: | Badge | What this means | Go to | |-------|-----------------|-------| | ![Offline](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/bambu-lab-badge-offline_2uifcp.png) | Client can't reach printer | [Printer shows Offline](#2-2-printer-shows-offline-in-client) | | ![Connecting](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/bambu-lab-badge-connecting_b74qos.png) | Client found printer but can't communicate | [Stuck on Connecting](#2-3-printer-stuck-on-connecting) | | Flickering between states | Multiple client instances | [Printer flickering](#2-5-printer-keeps-flickering) | | ![Online](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/bambu-lab-badge-online_k4kvnn.png) in client but **Offline** in SimplyPrint | Cloud connection issue | [Online in client but offline in SimplyPrint](#2-4-online-in-client-but-offline-in-simplyprint) | --- ## Quick reference | Symptom | Likely cause | Solution | |---------|--------------|----------| | Can't access client web interface | Client not running | [Start the client](#2-1-client-isnt-running) | | Client won't start or crashes | Antivirus or corrupt install | [Client won't start](#3-client-wont-start-or-crashes) | | Printer shows Offline in client | Network or config issue | [Check network](#2-2-printer-shows-offline-in-client) | | Printer stuck on Connecting | Access code or mode mismatch | [Check configuration](#2-3-printer-stuck-on-connecting) | | Printer keeps flickering | Multiple client instances | [Fix multiple instances](#2-5-printer-keeps-flickering) | | Flickers even with one client running | Another app also connected to the printer | [Other apps connected](#2-5-printer-keeps-flickering) | | Can see but can't control printer | Need Developer Mode | [Enable Developer Mode](#2-lan-only-mode-and-developer-mode) | | Was working, stopped after a change | Recent update | [Did you change something?](#2-did-you-recently-change-something) | --- ## Did you recently change something? If your printer was working and suddenly stopped, think about what changed. ### Updated printer firmware? After a firmware update: - You may need to enable **Developer Mode** - Your **access code** may have changed - check on printer and update client - Power cycle the printer See: [Printer stopped working after firmware upgrade](https://help.simplyprint.io/en/article/bambu-lab-printer-stopped-working-after-firmware-upgrade-cant-start-prints-anymore-pjmcrt/) ### Updated the client? If things broke after updating: - Check if antivirus quarantined the new version - Try restarting the client - Reinstall from [simplyprint.io/setup-guide](https://simplyprint.io/setup-guide#bambu:1) ### Changed network or router? - **New router/WiFi settings** - Printer may have new IP - **Changed WiFi password** - Reconnect printer to WiFi - **Enabled firewall or VPN** - Check required ports - **Moved printer to different VLAN** - Client and printer must be on same network ### Updated your OS? After Windows, macOS, or Linux update: - Client may not have restarted - check if running - Windows updates sometimes reset firewall rules - macOS may need re-granted permissions ### Moved to new device? - Make sure only **one instance** is running (not on both old and new device) - New device must be on same network as printers ### Started using another Bambu app? If you recently added **Home Assistant, Bambuddy, or another tool that stays connected to your printer**, it can compete with the SimplyPrint client for the printer's connection and cause disconnects. See [Another app connected to the same printer](#2-5-printer-keeps-flickering). --- ## 1. Client isn't running ### How to check **Windows:** Look for SimplyPrint icon in system tray (bottom right). Click arrow to show hidden icons. **macOS:** Look for SimplyPrint icon in menu bar (top right). **Linux / Raspberry Pi:** ```bash systemctl status simplyprint-bambu-client ``` ### How to start **Windows:** Search "SimplyPrint Bambu Lab" in Start menu. **macOS:** Open from Applications folder. See [macOS setup guide](https://help.simplyprint.io/en/article/bambu-lab-client-macos-setup-allow-open-on-startup-run-in-background-f9qd9e/) for background permissions. **Linux / Raspberry Pi:** Start according to how you installed it. ### Accessing web interface - **Same device:** `http://localhost:8000` - **Other device:** `http://:8000` > **Tip:** On Windows or Mac, double-click the tray icon to open the web interface. If port 8000 doesn't work, try 8001, 8002, or 8003. ### Client won't start or crashes **1. Check antivirus** Some antivirus (especially Windows Defender, Avast) block client files. - Check quarantine for SimplyPrint files - Add exception for SimplyPrint folder - Try disabling real-time protection **2. Reinstall** Download latest from [simplyprint.io/setup-guide](https://simplyprint.io/setup-guide#bambu:1). **3. Still not working?** Get your logs and see [Getting help](#2-getting-help). --- ## 2. Printer shows Offline in client Client can't reach the printer on your network. ### Power cycle first > **Try this first:** Turn off your printer, wait 30 seconds, turn it back on. This fixes many connection issues, especially on A1 Mini. 1. Turn off completely 2. Wait 30 seconds 3. Turn back on 4. Wait for WiFi connection Power cycling is also recommended after enabling LAN-only Mode for the first time. ### Check network Client and printer must be on the same network. | Problem | Solution | |---------|----------| | Printer on guest network | Move to main network | | Printer on different VLAN | Move to same VLAN | | Printer on 5GHz WiFi | Switch to 2.4GHz | **Quick test:** ```bash ping ``` If ping fails, fix network first. ### Check if IP changed 1. Find current IP on printer: **Settings > WLAN/Network** 2. Compare with IP in client 3. If different, update in client or re-add printer > **Tip:** Set static IP in router DHCP settings to prevent IP changes. ### Firewall and ports Required ports: | Port | Purpose | |------|---------| | 8883 | Printer communication (required) | | 990 | File transfers | | 322 | Camera (X1, X1C, X1E, H2D, P2) | | 6000 | Camera (P1P, P1S, A1, A1 Mini) | --- ## 3. Printer stuck on Connecting > **First:** Try restarting the SimplyPrint Bambu Lab Client - this often resolves connection issues. **How to restart the client:** **Windows:** 1. Open **Task Manager** (Ctrl + Shift + Esc) 2. Find and end all SimplyPrint processes 3. Start the client again from the Start menu **macOS:** ```bash launchctl stop simplyprint-bambu-client launchctl start simplyprint-bambu-client ``` **Linux / Raspberry Pi:** ```bash sudo systemctl restart simplyprint-bambu-client ``` Or reboot the device running the client. If still stuck on Connecting, there's usually a [configuration mismatch](#3-check-access-code). ### Check access code The access code lets client talk to printer. Must match exactly. **Find on printer:** | Model | Location | |-------|----------| | A1 / A1 Mini | Settings > WLAN/Network > LAN-only Mode | | P1P / P1S | Settings > WLAN/Network | | X1 / X1C / X1E | Settings > LAN Mode | | H2D / P2 | Settings > LAN Mode | > **Note:** On A1 series, enable LAN-only Mode first to see code. If all zeros, toggle LAN-only Mode off and on. If code changed, update in client or re-add printer. ### Check serial number Found in **Settings > Device** on printer. Must match exactly (case-sensitive). ### Check connection mode Printer needs **LAN-only Mode** and **Developer Mode** enabled. See [LAN-only Mode and Developer Mode](#2-lan-only-mode-and-developer-mode). --- ## 4. Online in client but offline in SimplyPrint Issue is between client and SimplyPrint cloud. ### Check internet ```bash ping simplyprint.io ``` ### Check client version Make sure client is up to date: [How to update](https://help.simplyprint.io/en/article/bambu-lab-integration-how-to-update-the-client-ql5f60/) ### Restart client Close and reopen the client. --- ## 5. Printer keeps flickering Printer switching between online/offline every few seconds? Probably **multiple client instances running**. ### Why this happens Two clients try to connect to same printer, "fighting" over the connection. ### How to fix **Windows:** 1. Check system tray for multiple icons 2. Open **Task Manager** (Ctrl + Shift + Esc) 3. End all SimplyPrint processes 4. Start client once 5. If persists, restart computer **macOS:** ```bash launchctl stop simplyprint-bambu-client launchctl start simplyprint-bambu-client ``` **Linux / Raspberry Pi:** ```bash sudo systemctl stop simplyprint-bambu-client sudo systemctl start simplyprint-bambu-client ``` ### Another app connected to the same printer Even with a single SimplyPrint client, flickering or random disconnects can come from **another app connected to the same printer at the same time**. Bambu Lab printers only allow a limited number of simultaneous local connections, so a second app fighting for the connection causes the same online/offline flicker. Common culprits: - **Home Assistant** (the Bambu Lab / ha-bambulab integration) - **Bambuddy** or other third-party monitoring or farm tools - A second **Bambu Studio or OrcaSlicer** left open watching the printer over LAN - Automations (Node-RED, scripts) holding a live connection to the printer **How to fix:** keep just one app connected to each printer for live monitoring. To use SimplyPrint, close or disconnect the other tool, or point it at a different printer. This connection limit is Bambu firmware behaviour, not a SimplyPrint issue. --- ## LAN-only Mode and Developer Mode For full SimplyPrint functionality: - **LAN-only Mode** - enabled - **Developer Mode** - enabled Without Developer Mode, you can see printer but can't start prints. **How to enable:** | Model | Location | |-------|----------| | A1 / A1 Mini | Settings > WLAN/Network > LAN-only Mode, then Developer Mode | | P1P / P1S | Settings > WLAN/Network > LAN-only Mode, then Developer Mode | | X1 / X1C / X1E | Settings > LAN Mode | | H2D / P2 | Settings > LAN Mode | > **Tip:** After enabling LAN-only Mode, power cycle your printer. Full guide: [LAN-only mode and Developer Mode - how to enable](https://help.simplyprint.io/en/article/bambu-lab-lan-only-mode-and-developer-mode-how-to-enable-xa0hch/) --- ## Using BambuStudio to debug Not sure if problem is SimplyPrint-specific? Test with BambuStudio. 1. Install BambuStudio on **same device** as client 2. Add printer with same IP, access code, serial number 3. Try to connect and print | BambuStudio | SimplyPrint | Problem is | |-------------|-------------|------------| | Works | Doesn't work | SimplyPrint client or cloud | | Doesn't work | Doesn't work | Network, printer, or firmware | | Can see, can't print | Can see, can't print | Developer Mode not enabled | --- ## Getting help ### Gather this first 1. **Client version** - [How to find](https://help.simplyprint.io/en/article/bambu-lab-integration-how-to-find-your-version-number-in-the-client-cl17rf/) 2. **Printer model and firmware** - Settings > Device 3. **Connection mode** - LAN-only + Developer Mode enabled? 4. **Client logs** - [Where to find](https://help.simplyprint.io/en/article/bambu-lab-integration-where-to-find-your-logs-18vmobp/) 5. **Screenshots** of errors ### Support - **SimplyPrint Discord:** [simplyprint.io/discord](https://simplyprint.io/discord) --- > Something unclear or missing in this guide? Let us know on [Discord](https://simplyprint.io/discord). --- ## Related articles - [Connecting Bambu Lab printers to SimplyPrint](https://help.simplyprint.io/en/article/connecting-bambu-lab-printers-to-simplyprint-xqlhtd/) - [Bambu Lab client setup troubleshooting](https://help.simplyprint.io/en/article/bambu-lab-client-setup-troubleshooting-guide-xb0jix/) - [LAN-only mode and Developer Mode](https://help.simplyprint.io/en/article/bambu-lab-lan-only-mode-and-developer-mode-how-to-enable-xa0hch/) - [Printer stopped working after firmware upgrade](https://help.simplyprint.io/en/article/bambu-lab-printer-stopped-working-after-firmware-upgrade-cant-start-prints-anymore-pjmcrt/) - [Where to find logs](https://help.simplyprint.io/en/article/bambu-lab-integration-where-to-find-your-logs-18vmobp/)