You Think that 7805 Will Heal Itself?

They Never Heal! I seldom beg…but I have to this time. Anyone who’s doing field service…please...when you pull a bad component, throw it out – or at least find a bucket and clearly label it, “Bad Parts I’m Hoping Will Heal.” How many times have you entered a site for the first time to find drawers full of components with solder on them (as if they’ve been removed from a circuit) or labeled, “removed” or “E-B short” or just “bad”. Here’s what I’ve found. No bad part has ever healed. Fuses stay blown. Transistors stay shorted and open diodes are open forever. So get rid of them. And the ones that can be fixed…send the choke off and have it rewound or get rid of it. What a time waster to have to re-declare a MOSFET DOA so that you don’t install it and find that the same symptom prevails, or worse, new ones pop up. It’s a simple request. Throw them out. If you really want to keep them, put them in that bucket or nail them to a piece of wood or curl their leads to make cute little bugs. It’ll save the owner countless billed hours and you lots of headaches. One important note: If there’s a possibility of an insurance claim, document every part failure and replacement and hang on to all of the parts until the claim is settled. If you want to take things one step further, do a real inventory. Right. Count ‘em all. First, you’ll be surprised what you have for emergencies and second, it makes emergency repairs a lot easier and faster. Of course, it helps to sort and store everything so it can be found, otherwise, it’s all for nothing. Now, the problem with all of this is that there’s never enough time – and ask the average owner if he/she’ll approve overtime so that you can take inventory and catalog, and the answer probably will be no. Maybe you can play back the part above about saving money on future repairs. That might get you an OK. Then again, maybe not.