Final answer:
If the customer's old tower PC doesn't always turn on and randomly shuts off, and the HDD and RAM memory tests are positive, the next hardware part to check would be the PSU (Power Supply Unit). Option D is correct.
Step-by-step explanation:
If a customer's old tower PC doesn't always turn on and randomly shuts off for hours, and the hardware tests for the HDD and RAM memory have both come back positive, the next hardware part to check would be the PSU (Power Supply Unit).
The PSU is responsible for supplying power to the PC's components, and if it is faulty, it can cause issues with turning on and random shutdowns. To check if the PSU is the problem, you can try replacing it with a known working PSU or using a PSU tester to measure the voltage levels.
If the issue persists even after replacing the PSU, then you can consider checking other parts such as the NIC (Network Interface Card) or checking for any loose connections in the system.
If a customer complains that an old tower PC doesn't always turn on and randomly shuts off for hours, and assuming that HDD and RAM memory tests come back positive, the hardware part to check next would be the PSU (Power Supply Unit).
The PSU is responsible for providing stable power to the computer's components. Symptoms like random shutdowns or power-on issues are often related to power supply problems. It's important to check for any visible signs of damage or wear, such as swollen capacitors, burnt components, or unusual noises. If the PSU is failing, it can't deliver the required stable power and may need to be replaced.