To replace a transformer, first turn off the power to the appliance, and unplug it from the power source, locate the position of the old transformer, remove it, and install the new transformer. Finally, reassemble the appliance.
The most crucial step when working with an electrical appliance is to disconnect it from its power source to prevent any accidental electrocution, even if it has a low power rating. For an appliance wired into the housing unit, identify its circuit breaker, and turn it off. Finding the transformer is generally easy, since most transformers are located at the end of the power cable leading into the appliance. However, if you fail to locate it, look for a wiring diagram of the appliance. From this point, remove the mounting casing, and disconnect all wires, bolts and screws that join the transformer to the unit.
Before installing a new transformer, ensure that it matches the old one, specifically in terms of the output voltage. This information is available at the back of the transformer. If they match, connect it back to the appliance the same way as the old one. At times, the new transformer may vary in size compared to the old one, and may thus prompt you to screw in new holes for it. There may also be numerous wires that prove to be confusing to join back, so use a voltmeter to ascertain that each wire goes to the right place.
Finally, join the mounting brackets together. The appliance is ready for use.