Hi Jeroen, Jeroen Bastemeijer skrev: > Hi Magnus, > > I totally agree with you. But doing a quick repair is more an art than a > science ;-) By having some feeling for common faults it is easier to > locate them.
Certainly, and I totally agree. Repairing electronics requires experience, and you need to gain experience in many diverse fields. Experience include typical error behaviour of components, designs and also knowing typical design types helps. Also learning to "cheat" in a safe way can also be rewarding. > The Huntron tracker was of use for equipment which was almost impossible > to service when under power. For example power-electronics with high > voltages and nice little radios which consisted of a stack of boards, > here it was impossible to probe around. The only solution was soldeing a > wire to a component, assemble the whole thing, switch on measure... for > testing another point, the whole procedure had to be repeated. Ok, for > some equipment we used extension cables, but it was not always possible > to use them. These days the 3,3 V is becoming more and more a high voltage power rail from which you can switch down to suitable voltages. 5 V is becoming scary high and 12 V or +/- 15 V is just unheard of. Sigh. > Some failures are very difficult to track: Firmware related problems. > The only solution to that, was finding a working unit and copy the > firmware to the faulty machine (e.g. EEPROM copying).... Making backup images of EPROMs etc. is a good thing. While the actual EPROM may not be faulty, even single bit errors may be the cause of much greif. > But as I indicated in the beginning: Repairing is more like an art than > a science. Over the years a whole bunch of tricks and strategies was > developed to locate the faults and fix them. Repairing needs a solid > background in electronics and a lot of experience. Certainly. I find myself being pulled into the lab every now and then to aid a debug-hunt. It seems that I am looking a little more out of the box than they do... pulling a spec in and point on the error or just turn the timebase knob to zoom in on the spurious signal... > But: When you manage to repair something, it usually gives a lot of > satisfaction! ;-) Certainly. Also, the rarer or more expensive it is, the greater satisfaction. Also beating someone to it can be gratifying. A common mistake is to invent too complex fault causes and try to proove those. It is usually a much simpler cause, but the engineer keep inventing complex causes. Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
