1. ASiIO4ALL may help if you had to use the conexant sound chip, which has no low-latency drivers of its own. ASIO4ALL can be useful under those circumstances, but can be a beast to get working. However, you don't need ADIO4ALL because you have a Roland interface that has its own ASIO drivers. Roland drivers are generally very good, work well and are far easier to get working than trying to configure ASIO4ALL.
2. Your lack of sound/buzzing may be a driver problem, it may be a hardware issue (even something as simple as a bad lead or an earth loop) or it may be a routing problem in how you have set up routing in Sonar or the interface itself. As a first step eliminate the driver problem by uninstalling ASIO4ALL and checking the only driver Sonar can see is the Roland one.
3. Having done that open Windows control panel/system and check in the devices list that there are no other audio devices showing other than the Roland. If there are, right click on them and disable (not uninstall) them. Video drivers often load HDMI audio drivers, and unless your screen has speakers and uses them, right click on the devices and disable them. Check the entries under game controllers as well because such drivers often turn up there.
4. Set the Roland interface to be your default sound device in Windows/control panel/sounds. Windows will now route all audio from any application through that. I suggest setting the Windows sound scheme to "none" and checking in the sound scheme tick boxes that all the Windows sounds are set to none. Now open iTunes, media player or similar and try playing back audio from your drive, a CD or even youtube. If that works OK you now know that the interface works properly and speakers etc. are connected correctly.
Once you've got that far we can then start to look at audio routing in Sonar and the dropouts/clicks and pops. There are free applications that monitor the PCI bus latency in the computer. PCI bus latency is the delays while Windows, drivers and hardware catch up with queued jobs and do their thing. If that latency is too high then the result is audio dropouts, pops etc. in Sonar or any other DAW. Wireless network adaptors are the most common cause of PCI bus latency and for that reason it's usually necessary to disable them in control panel/system. You may find that solves the dropouts problem on its own.
If not there's still many things that can be looked at, especially to do with power savings settings, but let's go one step at a time.