Dejavoo Z11: Troubleshooting Transaction Freezes - Solar... | terminalfaults.org

Technical Background:

Freezes after large transactions often relate to buffer overflows within the Z11's memory management during complex cryptographic operations, or voltage droops on the power rail during peak processing load. The ARM processor may be stalling. Transaction logs may contain checksum errors. Communications via the serial port may also be affected if this is the root cause of the lockup.

Symptoms:

Z11 unit freezes during or immediately after processing a large transaction. The screen becomes unresponsive, and no further input is accepted.

Possible Causes:

Insufficient RAM allocation for handling large transaction data.
Power supply voltage drop under heavy processing load.
Software bug or glitch within the transaction processing module.
Intermittent connection issue with the network interface causing transaction timeouts.
Corruption of the transaction log data stored on the internal flash memory.
ESD event during transaction input.

Solution:

1

Perform a hard reset by disconnecting the power cable for at least 60 seconds, then reconnect.
2

Verify the power supply is providing the correct voltage (typically 5V) and current. If possible, test with a known good power adapter of the same specifications.
3

Ensure the Z11 has the latest firmware version installed. Check for updates via the device's configuration menu or Dejavoo's support website.
4

Check network connectivity. Ensure the Ethernet cable is securely connected or the Wi-Fi signal is strong and stable.
5

If using a dial-up connection, check the phone line for noise or interference.
6

Minimize potential sources of electromagnetic interference (EMI) near the device, such as nearby motors or radio transmitters.
7

Contact Dejavoo technical support if the issue persists after attempting these steps.

Safety Warning:

Avoid operating the device in environments with high humidity or static electricity. Do not attempt to open the device's casing, as this will void the warranty and potentially damage the anti-tamper mechanisms. Safe Handling: Always disconnect the power cable before cleaning or moving the device.

Prevention:

Regularly clean the device's touchscreen with a dry, anti-static cloth. Ensure the power and network cables are free from strain and securely connected. Periodically check for and install firmware updates.

Expert Tip:

If freezing occurs specifically with high-value transactions, attempt to split the payment into multiple smaller transactions. This can bypass potential memory allocation issues. Also, check the Z11's communication logs for any error codes related to buffer overflows or memory errors. These may indicate the need for a firmware update or hardware replacement.

Frequently Asked Questions

•What are the typical power supply specifications (Voltage, Amperage) for the Dejavoo Z11?

The Dejavoo Z11 typically requires a 5V DC power supply with a minimum of 2A current.

•How do I access the system logs on the Dejavoo Z11 to check for transaction errors?

Accessing system logs usually requires administrative privileges and may vary depending on the firmware version. Consult the Dejavoo Z11's user manual or contact Dejavoo support for instructions specific to your device's configuration.

•What are the environmental operating conditions for the Z11 (Temp/Humidity)?

The Dejavoo Z11 is typically designed to operate within a temperature range of 0°C to 40°C (32°F to 104°F) and a relative humidity range of 5% to 95% (non-condensing).

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What are the typical power supply specifications (Voltage, Amperage) for the Dejavoo Z11?

•How do I access the system logs on the Dejavoo Z11 to check for transaction errors?

•What are the environmental operating conditions for the Z11 (Temp/Humidity)?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: