The vast majority of us understand next to nothing about power supplies — and that's exactly why, when you buy a computer, you'll almost always get it bundled with the worst power supply available. You won't know it's bad for years, until it stops working, and the cost savings for the seller are significant.
Power supplies die in one of two ways: a sudden explosion and instant death, or a slow decline in which the power they deliver gradually decreases — causing a corresponding drop in system performance.
The photos show a voltage tester for desktop computer power supplies.
The computer on the left is relatively new — just a few months old — and had started shutting down unexpectedly in the middle of the workday.
I compared the test readings between the existing power supply and a new unit of the same model (on the right). The existing supply shows lower voltage values alongside a higher Power Good (PG) signal delay compared to the new one.
Although the readings are still technically within acceptable range, the sheer fact that they had dropped so significantly within just a few months was enough to confirm that the unit was faulty.
Continued use of the computer in this state would almost certainly lead to further degradation until the power supply failed completely.
I found no explanation for the sudden shutdowns in the operating system logs, which left the power supply as the most likely culprit. Replacing it with a new unit did indeed solve the problem.
Next time you buy a computer, pay attention to the power supply. Spending an extra 100 ILS could save you a great deal of trouble down the road and keep your system performing at its best for years to come.