To isolate the problem, follow these steps:
The real nightmare isn’t the byte itself. It’s that 0x68 is often a sync byte in certain protocols (like ISO 7816 smart cards). Or the first byte of a multi-byte frame. Or just garbage left in the UART buffer from a previous reset.
You’re not just debugging a handshake. You’re debugging timing. Somewhere, your device started listening 2 milliseconds too early — catching the tail end of a previous transmission.
ser.write(b'\xFF') time.sleep(0.1) response = ser.read(10) if response == b'\x68': print("Echo received, now send SNRM") ser.write(b'\xE6\x...') # complete handshake
0x68 has common meanings:
The error "Unexpected response 0x68" is rarely a fatal hardware failure. It is almost certainly a configuration mismatch.
Immediate Action: Adjust the host baud rate to 9600 or 115200 and retry. If the error persists, update the host code to recognize 0x68 as a valid start-of-frame.
In the world of mobile repair and firmware flashing, the "Handshaking... Error Unexpected Response 0x68" is a common hurdle, often seen when using tools like UnlockTool to bypass FRP or flash Android devices. The Troubleshooting Story
Imagine you're trying to flash a device. You've connected everything, but the software hangs at "Handshaking" and throws error . Here is how to resolve it: Check the "Handshake" Cable
The "handshake" is the initial communication between your PC and the phone's BootROM. Error 0x68 often means the signal is weak or interrupted. Use a high-quality, original USB cable and avoid using front-panel USB ports on desktop computers—plug directly into the motherboard ports at the back. Driver Conflicts
If your PC "sees" the device but doesn't understand its response, it’s likely a driver issue. Ensure you have the latest MTK/SPD drivers installed. Many users find success by using a "Filter" in LibUSB-win32
to specifically capture the device's connection during the handshake phase. Force the Connection (The Key Combo)
Handshaking often fails if the device isn't in the correct mode (like BROM mode for MTK chips). Volume Up + Volume Down
while plugging in the USB cable. This "forces" the handshake to happen on the correct port. Software Environment
Sometimes, antivirus software or other phone managers (like iTunes or Samsung Smart Switch) interfere with the serial port communication. Disable these temporarily to give your flashing tool exclusive access to the USB port. If you’d like more specific help, let me know: are you using (e.g., UnlockTool, SP Flash Tool)? What is the of the phone?
were you trying to perform (e.g., Factory Reset, FRP Bypass, Flashing)?
I can give you the exact "button combo" or driver link for your specific device. How To Fix Unlocktool Handshaking Failed Error Fix 17 Jun 2025 —
The error "handshaking... error unexpected response 0x68" is a specific communication failure typically encountered when using Android servicing tools like UnlockTool, Chimera, or Pandora. It indicates that the device (usually a MediaTek or Qualcomm-based phone) sent a response byte (0x68) that the software did not expect during the initial boot-level handshake. Technical Breakdown handshaking... error unexpected response 0x68
Response 0x68: In low-level serial communication or BootROM (BROM) protocols, 0x68 is often an ASCII character ('h') or a status code returned by the device hardware. When the flasher expects a "ready" signal and gets 0x68 instead, it aborts the process.
Common Context: This happens most frequently during FRP bypass, Bootloader Unlocking, or IMEI repair procedures. Troubleshooting & Fixes
If you are seeing this error, follow these steps in order to resolve the communication mismatch: Force Restart (Battery Reset): Disconnect the phone from the PC.
Hold Volume Up + Volume Down + Power for 10–15 seconds to force a hard reset.
On some older MediaTek models, you may need to disconnect and reconnect the physical battery connector to clear the hung BROM state. Driver Integrity:
Ensure you have the latest LibUSB-Win32 filter drivers installed.
Use the UnlockTool Driver Installation Utility to ensure the "MediaTek USB Port" (or Preloader port) is correctly filtered.
Check for conflicting drivers from other tools like SAMSUNG USB Drivers or old Z3X drivers that might be hijacking the port. Hardware & Port Checks:
Switch to a USB 2.0 port (often blue USB 3.0/3.1 ports cause timing issues with handshaking).
Replace the USB cable with an original high-speed data cable. Software Update:
This error often occurs when the device firmware is newer than the tool’s database. Verify you are using the absolute latest version of your servicing software. Related Issues
Unable to Mount Storage: If the handshake succeeds but the tool later reports "failed to mount data" or "unable to mount storage," it indicates an encrypted or corrupted data partition.
Alternative Methods: If the automated tool fails with 0x68, attempt the flash using SP Flash Tool or MiFlash with the original stock firmware to restore a clean state. How To Fix Unlocktool Handshaking Failed Error Fix
The error "Handshaking... Error Unexpected Response 0x68" is a specific communication failure typically seen when using certain firmware flashing tools (like Miracle Box, SP Flash Tool, or Infinity-Box) to interact with mobile devices.
The hex code 0x68 generally indicates that the device's bootloader or security processor returned a signal that the software did not expect during the initial "handshake" phase. Common Causes
Secure Boot / Authentication: Many modern devices have a "Secure Boot" enabled. If you try to flash or read the device without a specific "DA" (Download Agent) file or an authentication file (.auth), the device rejects the connection with this error.
Driver Mismatch: The computer may be using an incorrect or outdated VCOM/Preloader driver, causing the data packets to be misinterpreted. To isolate the problem, follow these steps:
Hardware Connection: A loose USB cable, a damaged charging port, or insufficient power (low battery) can cause the handshake to drop midway.
Incorrect CPU Selection: If you have selected the wrong chipset (e.g., selecting MT6580 when the device is MT6735) in your service tool, the boot sequence will fail. Troubleshooting Steps
Use a Custom DA File: In your flashing software, manually select a "Download Agent" (DA) file specifically designed for your device model rather than the default one.
Disable Driver Signature Enforcement: If you are on Windows 10 or 11, you may need to disable digital driver signing to allow the VCOM drivers to function properly. Check Connection Mode:
Try connecting the device while holding Volume Up, Volume Down, or both buttons simultaneously before plugging in the USB.
Try a different USB port (preferably a USB 2.0 port on the back of a PC).
Verify Battery Level: Ensure the device has at least 30-50% charge; a low battery can cause the processor to "brown out" during the high-power handshake phase.
Use an Auth Bypass Tool: If the device has a MediaTek (MTK) processor, you might need a "Bypass" utility to disable the bootroom protection before the flashing tool can establish a handshake.
Handshaking... [ERROR] UNEXPECTED RESPONSE: 0x68 is a low-level communication failure commonly encountered when using mobile phone service tools (like MTK Bypass SP Flash Tool UnlockTool
) to flash, unlock, or bypass authentication on MediaTek-based devices (e.g., Oppo, Vivo, Realme, Honor). Meaning of the Error
The "Handshaking" phase is when the servicing software attempts to establish a connection with the phone's bootloader (BROM mode). The
code indicates that the phone sent a response the software did not expect or cannot process. This often happens if the hardware communication is unstable or if the bootloader state has been corrupted by previous failed operations. Common Fixes Drain the Battery
: For devices that are stuck or not responding (often showing a charging light but not turning on), letting the battery drain completely can reset the bootloader state. Force Restart into BROM
: Ensure you are entering the correct mode. This usually involves holding Volume Up + Volume Down
simultaneously while plugging in the USB cable to a powered-off device. Check Drivers : Use a reliable driver like the filter or official MediaTek USB VCOM
drivers. Ensure the device appears in Device Manager without errors. Swap Cables/Ports : Communication errors like
are frequently caused by poor data transfer. Use a high-quality original USB cable and try a USB 2.0 port instead of USB 3.0. Reflash Stock Firmware The real nightmare isn’t the byte itself
: If the device has a corrupted "rrecord" or boot partition, you may need to use a tool like
or the official manufacturer tool to return to stock MIUI/EMUI before trying to use third-party bypass tools again.
Which phone model and servicing tool are you currently using for this process? POCO M5s - Прошивки MIUI - 4PDA 21 Dec 2024 —
The error "handshaking... error unexpected response 0x68" is most commonly encountered when using Unlock Tool or similar software to service mobile devices (often Oppo or MediaTek-based phones). It typically signifies a protocol mismatch or a failure in the initial communication between the software and the device's bootloader. Primary Cause & Solution
This specific error is usually caused by missing or incorrect USB drivers, specifically the libusb-win32 or MTK drivers, which prevent the tool from correctly "handshaking" with the device in its pre-loader or brom mode. Standard Troubleshooting Steps:
Install LibUSB Drivers: Ensure you have the libusb-win32 drivers installed. Many tools require you to use the "Filter Wizard" within LibUSB to select the device while it is connected in its specific boot mode.
Check USB Connection: Use a high-quality data cable and try different USB ports (preferably USB 2.0 if available, as USB 3.0/3.1 can sometimes cause timing issues with these tools).
Disable Driver Signature Enforcement: On Windows, you may need to disable driver signature enforcement to allow the specialized mobile drivers to function correctly.
Device State: Ensure the device is in the correct mode (e.g., holding Volume Up + Volume Down while plugging in the cable) as required by the specific tool. Other Contexts
While less common, similar "unexpected packet format" or handshake errors can occur in other network-based environments:
IMAP/Email Migration: In tools like MigrationWiz, this error often means you are attempting an SSL connection on a port that only supports non-SSL (or vice versa).
SSH/Terminal: If seen in a terminal, it might indicate a mismatch in supported ciphers between your client and the server, which can sometimes be fixed by updating your SSH configuration to allow older or specific encryption types.
Are you using a specific mobile unlocking tool when this error appears? The handshake failed due to an unexpected packet format
Here’s a short, intriguing blog-style post based on that cryptic error message.
0x68 (hexadecimal) equals 104 in decimal, or the ASCII character 'h' (lowercase H).
However—and this is crucial—0x68 is not a standard handshake character.
So if your device expected 0x06 (ACK – Acknowledge) or 0x15 (NAK – Negative Acknowledge) and instead received 0x68, the protocol is broken. Your device is basically screaming: "I asked if you were ready, and you replied with the letter 'h' – I have no idea what to do with that."
The error message "Handshaking... error unexpected response 0x68" typically occurs during the initialization phase (handshake) between a host controller and a peripheral device. This error indicates that the host expected a specific acknowledgment byte (usually 0xAA or 0x00) but received the byte 0x68 instead.
This report identifies the two most probable causes for this specific byte value: