Showing results for 
Search instead for 
Did you mean: 
Honored Contributor I

The win7 device manager detects nothing when JTag is connected to laptop

I tried to use the JTag cable by connecting it to the USB port of my laptop. 

By following the instruction of driver installation: 

After the USB port is connected with the JTag cable, the "Windows Found New Hardware dialog box" should show up, or we should see a new item in the device manager show up, then we can proceed to install the driver for it. 


However, when I connect the JTag to USB port, there is nothing happening in my laptop. 

"Windows Found New Hardware dialog box" doesn't show up, and there is nothing new in the device manager. 

It looks like there is nothing detected in my laptop, so I can't do anything to change the driver setup for the JTag. 


There is no problems about the USB ports of the laptop since I have checked them with other devices. 


What should I do to solve this problem or is there any reference about it? 

Thank you.
0 Kudos
3 Replies
Honored Contributor I

I assume you already have Quartus installed... 


Open 'Device Manager' and look for an unknown device. Right click on it and 'Update Driver Software...', pointing at the drivers referenced in the article you quoted. 


If you can't find your USB Blaster in device manager then, perhaps, there is an issue with yours. 



Honored Contributor I

Dear Alex, 


Thanks for your response. 

Yes, Quartus is installed. 

There should be a unknown device when the JTag cable is connected to the USB port. 

However, there is actually no unknown device found in the Device Manager. That's the problem. (Neither the USB Blaster nor an unknown device shows up.) 

Therefore, I can do nothing to deal with the driver.
Honored Contributor I

You didn't mention a specific USB "cable". Is it Altera USB Blaster? Or any third party product? 


Presume you have checked correct operation of the USB port with other USB peripheral. 

Similarly you can check the cable, although is unlikely to become defective. 


An USB Blaster that has lost it's configuration data might appear as FTDI serial bridge under COM&LPT devices. 


You may want to check the USB device enumeration activities during plug-in with a diagnostic tool, e.g. a recent Wireshark version.