i once worked at a TV shop in the Boston area. there was this customer we had who would get discarded electronics by "dumpster diving", and bring the stuff to us to fix. since he brought us stuff to fix regularly, the boss would waive the $35.00 estimate charge. the boss, however made it a point not to tell the customer what we found wrong with it, and usually the customer was ok with that, and usually would pay about $50.00 to fix about half the stuff he brought in. some stuff was really far too gone to fix, and we would estimate over $100 for those (this was 30 years ago, so fees were much lower then than they are now). he brought in a small black and white TV one time, and it took me less than 5 minutes to fix it. a mylar cap in series with the yoke wasn"t properly soldered in, and came loose while i was doing my initial visual/mechanical inspection. the boss only charged $10.00 for the repair, but the customer wanted to know what was wrong with it. i wouldn't tell him and neither would the boss, just that it had been a bad connection we resoldered. the customer got irate and wouldn't pay for it, and the boss brought back the TV and told me to un-fix it and make the problem hard to find, so i unsoldered the wire on the cap, resoldered the pad to be exactly as it had been before, and super-glued the cap lead back in the hole so the end of the cap wouldn't pop up when the cap was nudged (which is how i found it in the first place). then i cleaned the board well, put the TV back together and gave it to the boss. the boss came back and said he decided that this customer would have to go back to paying the estimate fee, and if he didn't like it he could take his junk elsewhere. i learned somewhere else, that if you charge too little for a repair, people don't respect your work, but if you charge too much, they look for a "second opinion"