Related:

• Machines that have broken down will work perfectly when the repairman arrives.
• The repair man will never have seen a model quite like yours before. -- Murphy's Law No. 28
• When a program is working perfectly the programmer will not know what the heck is going on.
  -- Murphy's Sixth Law of Programming...
• Nagler's Comment on the Origin of Murphy's Law: Murphy's Law was not propounded by Murphy, but by another man of the same name.
• The ABCs of Appliance Repair: a) At the first sign of electrical or mechanical trouble, gently wipe the outside of the appliance with a damp cloth.
  This should correct the problem. b) If that doesn't work, don't do anything....
• Bicycle Repair Man, how can I ever repair you?" "Well, you don't need to, gov, it's all right.
  It's all in a day's work for ... Bicycle Repair Man. <Sniff!>" -- Monty Pytho...
• Everybody has a scheme for getting rich that will not work. -- Murphy's Law No. 33
• Murphy's Law is recursive. Washing your car to make it rain doesn't work.