USB-based update
The oscilloscope firmware files are identified by the prefix "CHD". Follow these steps carefully:
FNIRSI DSO-TC2 (a 2-in-1 digital oscilloscope and transistor tester), the most useful piece of information regarding firmware updates is that dsotc2 firmware upd
Once the transfer reaches 100%, the unit will usually perform a checksum validation. Do not disconnect power until you see a "Success" or "Complete" message on the screen.
Ultimate Guide to FNIRSI DSO-TC2 Firmware Updates: Fix Bugs & Unlock Features Ultimate Guide to FNIRSI DSO-TC2 Firmware Updates: Fix
: Press the power button to enter update mode; your computer should recognize it as a USB drive .
April 21, 2026 Version: v2.1.4
Unlike a smartphone or a computer, the D100 hardware tokens are "closed-loop" security devices.
: The device will process the file automatically. Once the progress bar hits 100%, the current mode is updated. Why Update? Community Observations Once the progress bar hits 100%, the current mode is updated
: Once the copy finishes, the system will automatically flash the code and restart into normal operation mode. Troubleshooting Common Errors
| Error Message | Likely Cause | Solution | | :--- | :--- | :--- | | | Driver not installed or bad USB cable.| Reinstall drivers. Try a different USB port (USB 2.0 preferred over USB 3.0). | | "Checksum Mismatch" | Corrupted download file.| Delete the updater file. Redownload it from the official source. Disable antivirus during download. | | "Timeout Error" | Low power or interference.| Charge the DSOTC2 for 2 hours. Disable Bluetooth/WiFi on your PC. | | Device freezes on logo | Interrupted previous update.| You must perform a "Recovery Mode" flash. Hold Power + Volume Down for 10 seconds, then reconnect to the updater. | | "No VIN recognition post update" | Firmware updated, but car database missing.| You likely need to also update the Vehicle Database file (separate download, usually an .iso or .db file). |