The repair method of AP unable to start and the method to prevent it from being unavailable
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Problem Description
If the yellow light of the AP is always on, it is stuck on the bootware interface and cannot be started. Here are several recovery methods for reference.
Process Analysis
1 Common Phenomena and Repair Methods of AP Failed to Start
1.1 The yellow light is always on after power on, but there is no output from the serial port
Cause: The basic segment is damaged, or the hardware is faulty.
Repair method: return to factory for repair.
Remarks: The lights on very few models are not on, and the serial port uses 9600 baud rate.
1.2 The yellow light is always on when the power is on, and the serial port prints "Boot ROM program does not exist."
Remarks: The lights on very few models are not on, and the serial port uses 9600 baud rate.
Repair method:
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System is starting... Press Ctrl+D to access BASIC-BOOTWARE MENU... Boot ROM program does not exist. Now start to download program.
=========================================== |<1> Modify Serial Interface Parameter | |<2> Update Extended BootWare | |<3> Update Full BootWare | |<4> Boot Extended BootWare | |<5> Boot Backup Extended BootWare | |<0> Reboot | ================================================== Ctrl+U: Access BASIC ASSISTANT MENU Enter your choice(0-5): 1
================================================== |Note:"*"indicates the current baudrate | | Change The HyperTerminal"s Baudrate Accordingly | |------------------------------------------------------|
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|<1> 9600(Default)*| |<2> 19200 | |<3> 38400 | |<4> 57600 | |<5> 115200 | |<0> Exit | =================================================== Enter your choice(0-5): 5 Baudrate has been changed to 115200 bps. //Modify the baud rate of the serial console software to 115200 Please change the terminal"s baudrate to 115200 bps, press ENTER when ready. The current baudrate is 115200 bps
============================================================== |Note:"*"indicates the current baudrate | | Change The HyperTerminal"s Baudrate Accordingly | |------------------------------------------------------| |<1> 9600(Default)| |<2> 19200 | |<3> 38400 | |<4> 57600 | |<5> 115200* | |<0> Exit | ============================================================================ Enter your choice(0-5): 0 =========================================== |<1> Modify Serial Interface Parameter | |<2> Update Extended BootWare | |<3> Update Full BootWare | |<4> Boot Extended BootWare | |<2> Update Extended BootWare | |<3> Update Full BootWare | |<4> Boot Extended BootWare | |<5> Boot Backup Extended BootWare | |<0> Reboot | ================================================ Ctrl+U: Access BASIC ASSISTANT MENU |
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|<5> Boot Backup Extended BootWare | |<0> Reboot | ================================================ Ctrl+U: Access BASIC ASSISTANT MENU Enter your choice(0-5): 2 //2 means to update only the extended section, or you can choose 3 to update the entire Boot, and then transfer the btw file through xmodem on the serial console software. (btw file acquisition path: download the version file corresponding to the AP model on the official website, the three-in-one version/V7 FAT/OASIS have all packaged btw files, and can be used regardless of AP mode) Please Start To Transfer File, Press To Exit. Waiting ...CCCCC Start xmodem transfer. Press Ctrl+C to cancel. 100% 578 KB 4 KB/s 00:02:24 0 Errors
Updating Extended BootWare? [Y/N]Y Updating Extended BootWare...Done.
=========================================== |<1> Modify Serial Interface Parameter | |<2> Update Extended BootWare | |<3> Update Full BootWare | |<4> Boot Extended BootWare | |<5> Boot Backup Extended BootWare | |<0> Reboot | =================================================== Ctrl+U: Access BASIC ASSISTANT MENU Enter your choice(0-5): 1
============================================================== |Note:"*"indicates the current baudrate | | Change The HyperTerminal"s Baudrate Accordingly | |------------------------------------------------------|
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|<1> 9600(Default) | |<2> 19200 | |<3> 38400 | |<4> 57600 | |<5> 115200* | |<0> Exit | =========================================== Enter your choice(0-5): 1 //Modify the serial port baud rate to 9600, and at the same time modify the baud rate of the serial port console Baudrate has been changed to 9600 bps. Please change the terminal"s baudrate to 9600 bps, press ENTER when ready. The current baudrate is 9600 bps
============================================================== |Note:"*"indicates the current baudrate | | Change The HyperTerminal"s Baudrate Accordingly | |------------------------------------------------------| |<1> 9600(Default)* | |<2> 19200 | |<3> 38400 | |<4> 57600 | |<5> 115200 | |<0> Exit | ============================================= Enter your choice(0-5): 0
=========================================== |<1> Modify Serial Interface Parameter | |<2> Update Extended BootWare | |<3> Update Full BootWare | |<4> Boot Extended BootWare | ========= Ctrl+U: Access BASIC ASSISTANT MENU Enter your choice(0-5): 0 System is starting... Press Ctrl+D to access BASIC-BOOTWARE MENU... Booting Normal Extended BootWare The Extended BootWare is self-decompressing....Done.
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|<5> Boot Backup Extended BootWare | |<0> Reboot | ============================================== Ctrl+U: Access BASIC ASSISTANT MENU Enter your choice(0-5): 0 System is starting... Press Ctrl+D to access BASIC-BOOTWARE MENU... Booting Normal Extended BootWare The Extended BootWare is self-decompressing....Done.
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1.3 The yellow light is always on after power on, and the serial port prompts "The image does not exist!"
Reason: APP version lost
Repair method: manually download the version, or create a dhcp server on the AC, configure auto-ap or manually create an ap template, and the bootware will automatically download the version.
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Press Ctrl+B to access EXTENDED-BOOTWARE MENU... Loading the main image files... The image does not exist! Loading the backup image files... The image does not exist! Loading the main boot and system image files... The system image does not exist! Loading images fails. Trying to get the IP address from the DHCP server...... DHCP server"s IP address is 192.168.0.100 Client"s assigned address is 192.168.0.205 DNS domain name got from DHCP server is DNS server"s IP address is 0.0.0.0 Default Gateway"s IP address is 192.168.1.1 This client"s subnet mask is 255.255.255.0 Change State : Idle to Broadcast Discovery Change State : Broadcast Discovery to Join Change State : Join to JoinAck Change State : JoinCfm to Image Download ........................
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1.4 The yellow light is always on after power on, and the serial port prompts "Last delete app(system.bin) size is XXXX
Reason: The APP failed to start continuously, and the Bootware actively deleted the version.
Repair method: Same as above.
1.5 The yellow light is always on when the power is on, and the serial port printing stops at "System image is starting..."
Information collection methods:
First turn on keyboard capitalization, click the ESC, K, D, B four buttons in turn to enter the kdb view, and execute dmesg. There are a lot of printed information, press the space several times to collect all the information.
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Entering kdb (current=0xc05c1460, pid 0) on processor 0 due to Keyboard Entry [0]kdb> dmesg
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2 Preventing AP from becoming unavailable Introduction
2.1 Bootware active/standby mechanism
After the main bootware is damaged, the single board will automatically start from the backup, and the main and standby synchronization will be performed, which greatly improves the system reliability.
11AX product wa6600 series extension section supports active/standby, basic section does not support active/standby, other 11AX series products both basic section and extended section support active/standby.
The product will strictly control the update of the basic segment to reduce the probability of updating the basic segment after leaving the factory. As long as the basic segment is not damaged, the device can be repaired through the serial port.
2.2 There is a rollback limit when the AP updates the version through AC and cloud, so as to avoid downgrading to the defective version
When the AP has a chip replacement, or if a major defect is found in the released version, the defect will be repaired in the new version in time, and the rollback limit will be increased. Version.
The rollback limit function is added through the cloud-based update version, which is incorporated into the R2449 version for the first time.
2.3 CAPWAP restarts after 6 consecutive timeouts, and Bootware actively tries to update the version
When there is a defect in the APP version, for example, when the wired port is unreachable, the AP cannot automatically update the version, resulting in bricking. With this mechanism, it will trigger Bootware to automatically download the version to avoid becoming unavailable.
2.4 The AP failed to start 16 times in a row, Bootware actively deleted the version and entered the download process
When the APP version cannot be started normally, Bootware will automatically delete the version, enter the download process, and download the new version to prevent the AP from becoming unavailable.
2.5 AP power-on bootloader (header firmware) changed from automatic update to manual update
As the complexity of the chip increases, the main chip manufacturer will provide a short power-on boot program, which we call the header firmware. The header firmware will not be updated after leaving the factory. Currently, Qualcomm’s header firmware does not support backup. If the header firmware is damaged, it will cause the device becomes unavailable, Broadcom's header firmware supports backup, and when one of them is broken, it can be started from other backup headers.
Now, for the newly developed 11AX products (WA6300A, WA6500A, WA6500B, etc. series), the header firmware has been stripped from the basic section, and will not be updated with the update of the basic section. The latest header is shipped from the factory, which improves product reliability. When the header firmware must be updated in the future, the header can be updated through the command line.
For old 11AX products, the header will not be updated at present. The latest header is shipped from the factory. Unless the device is damaged, it will not become unavailable
Solution
See Process Analysis