The most common reason UPSes fail, in our environment, is the batteries go bad.
To keep the power supply cool. If there were no fan the power supply would overheat and fail.
Power supplies don't fail. Idiot.
There are too many possible causes of failure to comment on them here without further information not provided in your question. There can be hundreds of different components in a computer power supply, each of which fail for different reasons and produce different symptoms in the power supply. Ultimately all electronics fails due to "old age" (just like people).
Bond it to a standard regulation fail-proof always-running generator.
Personally, I wouldn't use less than a 300 Watt power supply in that situation. But then, I never use less than a 500 Watt power supply when replacing a power supply or building a computer. The advantage is, the larger power supply can easily handle the load and will not run as hot. Since electronic components typically fail more rapidly when they get hot, the larger power supply will usually last much longer. But that's just a suggestion.
First, let me clarify the question: You want to use a 16V, 4.5 amp power supply to operate a device that uses 16V, 1.5 amps. That's not a problem, the larger power supply simply has the capacity of 4.5 amps, meaning that you can use anything UP TO 4.5 amps. On the other hand... if you want to try using a device that pulls 4.5 amps, using a 1.5 amp power supply... sorry, won't work out well. That would overheat the power supply and it would fail.
Not usually. Any electrical part can go bad though. Usually if electronics are going to fail it is within the first 24 hours or so. The only time I had to change a power supply is because I wanted more power.
the computer will not switch on. May be the SMPS fail leading to a huge spark.
An electromagnet would stop working if the electrical current flow is interrupted or if the power supply is disconnected. Additionally, if the coil overheats, it can damage the insulation and cause the electromagnet to fail.
Computer power supplies today do not need daily maintenance. They do need a free air flow to circulate through the power supply to prevent overheating. If there is a filter to prevent dust fro getting in to the power supply, it should be kept clean so that air flow is not restricted. If parts of the power supply get too hot they may fail to function properly or they may burn out.
the most likely cause of that would be the power steering pump failing.
Fianna Fail came to power in 1932.