Why USB-Blaster II does not work after closing the Quartus® Programmer Hardware Setup window?

Description

When using Quartus® Prime Standard Edition to program a MAX® 10 FPGA device with a USB-Blaster II, changing the Hardware Setup frequency from the default 24 MHz to 16 MHz and then closing the Hardware Setup window with the Close button may cause the USB-Blaster II to stop functioning.

Resolution

Here are some practical solutions you can try to resolve the issue:

1. Restart the JTAG server.

jtagserver --stop 
jtagserver --start

2. Unplug and replug the USB-Blaster II.

3. Kill lingering processes such as the JTAG server or Quartus Programmer process.

jtagserver.exe 
quartus_pgm.exe

4. Change the clock frequency of the USB-Blaster II download cable to lower frequency like 16Mz and 6Mz. Related KDB: How do I change the clock frequency of the USB-Blaster II download cable? | Altera Community - 342304

5. Avoid USB conflicts by disconnecting other USB serial devices, especially FTDI or USB-UART adapters, and avoid opening COM ports or serial terminal applications while programming.

6. Try a different USB port and connect the USB-Blaster II directly to the PC instead of through a USB hub.

7. Reinstall the driver from the Quartus installation folder or try an older or known-stable driver version.

8. Avoid mixing drivers from multiple Quartus versions.

9. If a USB hub is required, avoid poor-quality or legacy USB 1.0 hubs.

10. If a clone USB-Blaster is being used, replace it with a known-good cable.

11. If none of the above steps recover the problem, reboot the system.

Possible root causes:

1. JTAG server gets stuck and keeps the USB-Blaster II claimed.

• The device can appear normal in the operating system but remain inaccessible from Quartus Programmer.
• Restarting Quartus alone often does not recover the cable.

Fix:

jtagserver --stop jtagserver --start

• Or kill the process via Task Manager.

2. USB or driver conflicts with other devices.

• Conflicts with other devices, especially FTDI or USB-UART adapters, can break the USB-Blaster II mid-session.
• Opening a serial terminal can trigger the failure.
• This behavior is reported more often on Windows 64-bit systems.

Fix:

• Disconnect other USB serial devices.
• Avoid opening COM ports or serial terminal applications while programming.
• Try a different USB port with a direct connection instead of a USB hub.

3. Driver bugs or Quartus version mismatches.

• Driver bugs or Quartus version mismatches can prevent Quartus Programmer from detecting the cable.
• Known bad driver versions or incompatible Quartus releases can cause the Programmer to lose the cable or prevent the standalone Programmer from detecting it.

Fix:

• Reinstall the driver from the Quartus installation folder.
• Try an older or known-stable driver version.
• Avoid mixing drivers from multiple Quartus versions.

4. USB hub or signal quality problems.

• USB hub or signal quality problems can cause the USB-Blaster II to disappear after use.
• This is reported more often with poor-quality hubs or legacy USB 1.0 hubs.

Fix:

• Plug the USB-Blaster II directly into the PC.
• Avoid poor-quality or legacy USB 1.0 hubs.

5. Clone USB-Blaster hardware.

• Clone USB-Blaster hardware can be unstable due to timing issues, firmware quirks, or driver incompatibilities.

Fix:

• Replace the clone USB-Blaster with a known-good cable.

6. Closing Quartus Programmer leaves the cable in a bad state.

• Closing Quartus Programmer can leave the JTAG server running.
• It can leave the device handle locked.
• It can trigger USB re-enumeration issues on the USB stack.
• When Quartus Programmer is reopened, it may not be able to reattach to the already claimed cable.

Fix:

• Unplug and replug the USB-Blaster II.
• Kill lingering JTAG server or Quartus Programmer processes.
• Reboot the system if the cable is still not detected.