The answer to 'irrigation system bare spots' is that there are several common causes, including improper sprinkler head placement, broken or clogged sprinkler heads, inadequate water pressure, and soil compaction. Symptoms of these issues can include dry, patchy grass or exposed soil in certain areas of your lawn.
To troubleshoot and resolve bare spots, you may be able to DIY some basic maintenance like adjusting sprinkler heads, clearing clogs, and aerating the soil. However, more complex problems like pressure issues or major system malfunctions may require the expertise of a professional landscaping or irrigation technician.