I have tried everything and cannot get my audio button to turn back on...I have Sonar Home Studio XL7..( I know it's old )...and run into this problem from time to time...but have had no luck in resolving this time...
I am using Line 6 Tone port UX2 as audio interface....( all drivers are updated and current )...and it works just fine
I have connected a new USB cable ( that didn't work ) 
Cakewalk options audio is set to ASIO 
in/outs are  checked for Line6 toneport ux2
I am using a laptop ( Toshiba ) and the sound card is working...
 
any thoughts on what else I can do what be appreciated 
please reply if any questions
 
thanks in advance....Greywolf20
 

Back in the day with early Sonar - I think you used to be able to delete the AUD.ini file and it would re-build using defaults and re -task the Audio device and re-profile it. I'm not sure if that is a viable method with home studio - but it may be an avenue to look for with some googly research.

our Line 6 Tone Port should be your functioning sound card. Is the Tone Port your default setting in Sounds in the Control Panel? What Windows version are you on? You used to get a blank just by having your interface on a different USB in XP. Is everything set up in Preferences>drivers in HS7XL?

I find occasionally that Sonar won't see my USB interface when Windows and everything else will. That's when I think maybe Sonar is just being picky or something.
 
If the above doesn't work, try:
1) Close and reopen Sonar
2) Power OFF/ON the interface
3) Turn off WiFi and all internet connections
4) Defrag the HDD
5) Disable onboard sound
6) Reboot the system
7) Pull your hair out (omit if you have no hair)
 

Thanks for the replies....I'm using Windows Vista ...tone port is default setting for both HS7XL and on the tone port itself....the usb is plugged into the same port it's always been plugged into ....would you guys suggest at this point to maybe re-install both the Cakewalk HS7XL and Toneport UX2 ( my songs and tracks are already stored on external hard drive....i assume I can export UX2 user tones also ...haven't checked yet ) ..I really don't want to ..but I will if that's what needs to be done....
the error I get when I press play on HS7XL is this...
"unable to open audio record device.device may not support the current projects audio format or may be in use
for help please visit:
cakewalk.com/support/hardware setup/
or contact cakewalk technical support"
I tried opening many different projects that i've worked on in the past...and I get the same error message everytime...
thanks again for trying to help...any suggestions ...Greywolf20

Ensure that both SONAR and the UX are using the same sample rate and bit depth.
Confirm that you're using Line-6's ASIO drivers and not ASIO4All.

Just wanted to say thanks for the help...i'm back up and running...I downloaded Line6 4.2.7.1. Driver ( which was not the default current driver in line6 monkey )...and also corrected  / matched sample rate ...everything working fine now...thanks again ...there's no place else to go when a problem comes up...so the help is really appreciated ...Greywolf20