Explanation
The issue of video but no audio on a projector in a conference room can be resolved by utilizing an HDMI connection between the PC and the projector. HDMI supports both video and audio signals and is commonly used to connect a PC to a projector for presentations. Changing the input on the projector to VGA, changing the output on the PC to DVI, or modifying the projector's refresh rate will not resolve the issue. References:
CompTIA A+ Certification Exam: Core 1 - Objective 2.5

Explanation
A printer drum is a component of a laser printer that transfers the toner to the paper. It is a cylindrical metal or plastic piece that is coated with a photosensitive material. The drum is charged by a laser beam, which creates an electrostatic image of the document to be printed. The toner then sticks to the charged areas of the drum, and the drum rolls over the paper, transferring the toner to the paper and creating the printout1.
If the printer drum is damaged, worn out, or dirty, it may not be able to transfer the toner properly, resulting in blank pages. According to some web search results23, some signs that a printer drum needs to be replaced are:
*Faint, light, faded, or blank printed pages
*Streaks, spots, or lines on the printed pages
*Error messages indicating a drum problem
To fix this issue, the technician may need to clean or replace the printer drum. Some web search results12 provide instructions on how to perform a manual drum cleaning or replacement.
Printer ink is not a likely cause of the issue, since the user has already tried installing different toners and the issue persists. Toner is the powder used by laser printers, while ink is the liquid used by inkjet printers. They are not interchangeable4.
Environmental temperature is not a likely cause of the issue, since most printers can operate in a wide range of temperatures. However, extreme temperatures may affect the quality and performance of some printers. For example, high temperatures may cause ink to dry out or toner to clump, while low temperatures may cause ink to freeze or toner to become brittle.
Corrupted printer drivers are not a likely cause of the issue, since they would affect the communication between the printer and the computer, not the printing process itself. Corrupted printer drivers may cause errors, delays, or incorrect outputs, but not blank pages.

Explanation
A defective battery is the most likely cause of a mobile phone that gets really hot to the touch, does not retain a charge, and is slow while charging. A defective battery can cause the phone to overheat and may also cause performance issues. References: CompTIA A+ Certification Exam Objectives 1001, 2.14

Explanation
correct answer is "Overclocking" and "Reduce CPU Clock speed" CPU is at 4.5 Ghz when normal is 3.2 Ghz.
Overclocking too much can cause freezes, and this is a gaming computer so the user probably took it too far.
http://blog.logicalincrements.com/2018/12/4-troubleshooting-tips-overclocking-pc/

Explanation
HDD fragmentation is a condition where the data on a hard disk drive (HDD) is not stored in contiguous clusters, but scattered across different physical locations on the disk. This happens when files are created, modified, or deleted over time, leaving gaps and fragments of data on the disk. HDD fragmentation can affect the performance of the PC, especially when accessing large files that require more disk operations to read or write12.
According to some web search results123, some signs and symptoms of a heavily fragmented HDD are:
*Longer load times for files and programs
*Graphics-heavy apps and games take too long to load new windows or process new environments
*Reduced disk space and efficiency
*Increased disk noise and temperature
*Accelerated disk wear and failure
To fix this issue, the user can use a tool called Disk Defragmenter, which is built-in in Windows. Disk Defragmenter rearranges the fragmented data on the HDD so that it is stored in contiguous clusters, improving the disk performance and reliability1. Disk Defragmenter can run on a schedule or manually by following these steps1:
*Open Disk Defragmenter by clicking the Start button. In the search box, type Disk Defragmenter, and then, in the list of results, click Disk Defragmenter.
*Under Current status, select the disk you want to defragment.
*To determine if the disk needs to be defragmented or not, click Analyze disk. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
*Once Windows is finished analyzing the disk, you can check the percentage of fragmentation on the disk in the Last Run column. If the number is above 10%, you should defragment the disk.
*Click Defragment disk. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
*Disk Defragmenter might take from several minutes to a few hours to finish, depending on the size and degree of fragmentation of your hard disk. You can still use your computer during the defragmentation process.