CompTIA 6-Step Troubleshooting Process:
1. Identify the problem.
2. Establish a theory of probably cause. (Question the obvious)
3. Test the theory to determine cause.
4. Establish a plan of action to resolve the problem and implement the solution.
5. Verify full system functionality and if applicable implement preventative measures.
6. Document findings, actions, and outcomes.
Writing a knowledge base article in the ticketing software would help document the root cause of the application error and the steps taken to resolve it, which can help other technicians resolve similar issues in the future. This is an example of knowledge management best practices. Reference: CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition, Chapter 6

The most common reasons you may be seeing the "No Signal" message: The projector and the source device are not connected correctly.
The first action should be to check the video cable and replace it if necessary, as the error message suggests that the projector is not receiving a signal from the laptop. Verifying that the projector is turned on and checking the bulb would come after verifying the video cable.

Device interference is the most likely cause of the wireless connection dropping or becoming slow. Interference can come from other wireless devices, microwave ovens, or physical barriers like walls and metal objects. Hidden SSID, Ethernet port flapping, and high ISP latency are not likely to cause this issue.
Wireless interference from other devices can cause a drop in wireless connection speed and stability. In a small office environment, there may be several wireless devices competing for the same bandwidth, causing the issues described. Reference: CompTIA A+ Certification Exam Core 1 Exam Objectives - 3.7 Given a scenario, troubleshoot wired and wireless networks with appropriate tools

The screen rotation is locked. If a user's touch-screen tablet is having an issue with screen orientation, it could be due to screen rotation being locked in device settings.
If the screen rotation is locked, the touch-screen tablet will not rotate the screen when the device is turned. This can usually be unlocked in the settings or by pressing a specific key combination. Reference: https://www.howtogeek.com/254132/how-to-enable-screen-rotation-on-windows-10/

If the printed text is not adhering properly to the paper on a laser printer that has had repairs previously for scanning issues, the fuser should be replaced to resolve this issue. The fuser is a component of the printer that uses heat and pressure to fuse the toner onto the paper. If the fuser is not functioning properly, the toner may not adhere properly to the paper.