I found a weird problem with my Roland Quadcapture. 
 
I plug it into my desktop (all usb's back and front, so it is powered) and the lights come on, except my microphone, no signal.
I plug the same preamp, no changes, into my laptop. The mic pops in fine. Same preamp setup. (no hi-z, phantom power on). One works one doesn't. 
 
I thought it might be the drivers, but I popped in the correct drivers on my desktop and still no signal. It recognizes that the Quad capture is there, the software pops up,there's just no signal from mic. I can hit the auto-sense button from the software. Nothing coming from the mic. I unplug the mic and I get a minor bump in the input level, probably just the sensitivity from pulling a mic. But, no actual received audio.
 
Right now, I have a workflow where I record audio through laptop and use an external hard drive to get it to my desktop. I'd love to be able to skip that step.

Any help would be awesome!
 
 

I suppose the first obvious question is if both laptop and PC are on the same operating system ?  It would probably be helpful to include details of both laptop and PC to give people an idea what your working with.

Sure. The Laptop is Windows 7 Professional. The Desktop is Windows 8.1 
 
I figured maybe it was a driver problem, so I reinstalled the desktop driver with the specified Roland driver for 8.1. No signal from microphone, yet the preamp is powered. 
 
Hope that helps. Since it works fine on the laptop with the same chord setup, does it limit it to the software? Could it still be a hardware issue? 

Did you check in Sonars preferences to see if it is the device selected? Is ASIO mode active.? 
 

Uninstall the drivers for the Quad- Capture and then restart the computer.  Install the latest drivers for Windows 7 for the laptop.
 

When installing the driver, you must log on as a user with administrative privileges on your computer.
• Close system monitoring/anti-virus software before installing. If system monitoring software such as anti-virus programs are installed on your computer, you must close them until you’ve finished installing the driver.

You can right click on the setup file (exe) and select, Run as Administrator to install as the Admin.

• Disconnect any USB connecting devices—except your keyboard and mouse
• Install the QUAD-CAPTURE USB Driver Ver. 1.5.2 for Windows 8/8.1/7/Vista/XP  for the Win 7 laptop

 Don't plug the quad Capture into the laptop until you are notified by the software being installed.
 
This should be all it takes. 

Take note of your Sample Frequency,  44.1 should be good enough and allow for 4 channels to be used.
 
Finally, Connect your QUAD-CAPTURE directly to your computer--do not connect the QUAD-CAPTURE through a USB hub.
 
Sampling Frequency = 96 kHz, 48 kHz, 44.1 kHz
Recording: 4 channels
Playback: 4 channelsSampling Frequency = 192 kHz
Recording: 2 channels
Playback: 2 channelsI use an Octa-Capture and this is how I installed mine and it works great.Good luck.  

It sounds to me like the quad is not seeing enough power so it is not allowing phantom power. I had an old m audio interface that IIRC would only allow ohantom power if it was plugged in to the wall. I know that isnt exactly your problem but might be related. I dont think all powered usb ports are created equal. Could be that the laptop is providing more usb power than the desktop.  I have read -but not seen- that there is sometimes a BIOS option to adjust the usb power. You could look at BIOS and see if you have an option there or try using a powered usb hub. 

One question we never asked is, What type of microphone do you have?
 
Give the name and the model please