Recently, I had a client come to because his computer would not start up and he was not sure of the cause. After a quick inspection of the system I determined that it was the power supply had gone bad and needed to be replaced.
There are several symptoms that can occur when a power supply is not working or is not functioning properly, though in many situations there may be no warning before the power supply dies.
- Signs that the power supply is bad or not functioning properly:
- Machine does not boot or boots and beeps and then shuts back down.
- No power or lights turn on when pressing the power button.
- The fan(s) on the back of the power supply are not working (not spinning or are making noise). In many cases the power supply will still work with a noisy fan but it is usually a symptom that the power supply is close to failing.
Replacing a power supply is fairly straight forward process though if you don’t feel conformable working inside you computer I recommended bringing the machine to a repair shop.
The basic steps for replacing a power supply:
- Unplug the computer.
- Remove computer case cover.
- Depending on the manufacturer the case will either slide off or require the removal of screws.
- Record the connections from the power supply to the motherboard and components. Typically, there is at least on connection to the motherboard but there can be more. Then there is a connection to each device -CD, hard drive, DVD drive and floppy drive.
- After recording the connections unplug all the devices from the power supply.
- Next the power supply needs to be removed from the system. There are usually (depending on the model) a couple of screws on the back holding the power supply in place. In addition, there can be clips or screws inside the machine holding the power supply in place.
- Note: In order to make sure you get the correct replacement if you are not sure is to take the old power supply to a computer supply store and have them provide you with the replacement. If that is not possible contact the manufacturer of the machine directly to make sure the replacement is correct.
- Place the new power supply in the machine and anchor back into place.
- Re-connect the power supply to the motherboard and components.
- Replace cover, plug-in and boot.
If all goes well you should be able to plug in the machine and, hopefully, have power and a working computer!


















