GPIB-USB-HS Intermittent

[emma123456]

Hello 

I have two GPIB-USB-HS which I have plugged in (one at a time) to a Windows 7 (64 bit) computer with NI-488.8 drivers installed. However, on this particular computer, these devices (both of them) very quickly stopped working and started alternating between showing the yellow ready light and the green active light very quickly and alternately appearing and disappearing in the Device Manger.  Initially, only one of the controllers was doing this, so I swapped to the second GPIB-USB-HS, and it started doing the same thing (after showing a solid "ready" light for 5 minutes, right when I started trying to use it for control). 

I took the two controllers and plugged them into a different computer and they both display the same intermittent behavior, with the vanishing and appearing in the device manager and the alternating ready and active lights. 

I have tried the following and it has not solved the problem: 

1. Uninstalling and reinstalling the NI-488.8 drivers

2. Rebooting the computer

3. Using a different USB port (tried them all)

4. Setting the USB port power settings to disable automatic shutoff of the USB port to save power. All USB ports are 500mA ports. 

Any ideas? I'm really stuck on this one. 

Thank you for your assistance. 

[nyc_(is_out_of_here)]

Do you see any errors in Windows 7's Device Manager?

[emma123456]

No, the device manager says the device is working properly. I've tried uninstalling the driver from the Device Manager and letting it re-install. The re-install works but then the problem reappears immediately upon completion of the driver installation. 

[RichardG100]

Have you tried using a 32-bit computer? If possible try Windows XP?

Also, when you started the control, were you using Excel VBA? Or another type of application.

Thanks.

[JasonSmith]

I have several questions:

1. Do you see this behavior even with nothing connected to the GPIB end of the GPIB-USB-HS?
2. Are these controllers you have owned and successfully used for some time, or were they recently acquired?
3. If these are new to you, were they acquired new from National Instruments, or through another source? If from another source, were they sold as used or new devices?