Approach the ailing equipment in a confident manner. This will give the equipment the mistaken idea that you know what you are doing. It will also impress anyone who is watching and if the equipment should suddenly start to work properly, you will be credited with its repair.
Wave the service manual at the equipment. This will make it assume you are at least familiar with the source of knowledge.
In a forcible manner, recite Ohm's law to the equipment. (Caution: Refer to a reliable text to be sure of your knowledge of Ohm's law). This will prove to the equipment, beyond a shadow of a doubt that you possess some technical knowledge. This is a drastic step and should only be attempted if the first two steps fail.
Disturb the equipment slightly. This may require anything from a one foot to a five foot drop onto a concrete floor. Be sure you do not mar the floor.
Brandish a large screwdriver in a menacing manner. This will frighten the equipment and demonstrate your knowledge of the deadly 'short circuit' technique.
Add a transistor circuit even though the equipment uses tubes. This will prove to the equipment that you are familiar with design techniques and confuse the equipment thereby increasing your advantage. If this doesn't work, proceed to the final and most drastic step.