I remember working for a company that imported cheap radios. I took my seat with the other 20 or so techs repairing radios. Most quotas were in the 20 range while I was only repairing 3 or 5 radios a day. Thinking I would be handed my pink slip I asked the tech next to myself how he was repairing so many radios? He pointed to my draw where I had saves some diagrams off the back of some of the radios. There is your problem he said. You are over thinking wasting time. You can measure 6 transistors faster than you can think if they are RF , audio or IF. In short stop thinking and start measuring. When I looked around I could see that the other tech were measuring not thinking. I took his advise and my quota when up from 3 a day to 10. A lesson I did not forget and still use today. I would like to know if others have found this to be true.