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Repair clinic - repairfaq

Science on the Web – Part Four, Repairfaq.org – Repair Clinic



Repair Clinic – read repairfaq, old but never outdated.

Living in the digital age does not mean we have stopped thinking, breathing and repairing electronic equipment. A repair clinic for consumer goods or possibly any electronic gadget under the sun, is often every young person’s dream, possibly for their own ego but more likely, accepting a challenge. Good solid technical staff are hard to come by. When you do find them you can be rest assured they have browsed through the pages of Samuel M. Goldwasser’s repairfaq.

Repair clinic - repairfaq
McIntosh MC275 Tube amplifier – Credit: Fred von Lohmann

Sci.Electronics. Repair(frequently asked questions) is possibly one of the most widely visited websites in the last ten to fifteen years. It has a wealth of information covering techniques and circuitry used from the dark ages until current.  Repairfaq.org site features Samuel M. Goldwasser’s latest and greatest “Notes on the Troubleshooting and Repair of…” series of comprehensive repair guides for consumer electronics, common household products and even articles on laser. What makes repairfaq totally credible is the lack of bells and whistles and as advertised by the author, is a fluff free zone.

From a technical viewpoint, no matter how proud and clever you are, reading through the pages affiliate to monitor, TV and audio repair makes one realise how much we have forgotten. One of the oldest and common mistakes any DIYer can make is the slip of a test probe on a live circuit. If anyone tells me they have not done this, they are lying.  😉 Measuring FET voltages in high energy circuits is also something most TV engineers have done at some stage or other with disastrous results. Often a good working FET is found to be faulty. Most of these silly mistakes that we do can be stopped in their tracks by having a good idea as to the inner workings and the what, why and when to measure. Sounds simple doesn’t it?

Repair Clinic – phase two. Old tricks die hard!

Even if you are a PhD, do yourself a favour and read the articles – they are interesting. For me, the older circuits will always bring about a flash of memory, a recyclable piece of information buried deep in the brain.  With television, checking whether a capacitor is leaky was often done by bridging a known good one across the suspect component’s terminals. It’s not a trick I would use on modern circuitry – often the circuits are just not as robust as the older switching and flyback supplies. In video circuits possibly but most modern equipment is digital and SMD (surface mount) – the only high energy circuits are in the power supply. In years to come we will have new ways to test these but the unfortunate aspect to this is that modern equipment should be trashed and not repaired. I fear for our landfills, already a mess.

Repair Clinic – Phase Three. Essential reads – safety in the workplace

Repairfaq always has a comprehensive safety and safety guidelines column – for the newbie this is essential to read. For the well established technical guru this is still essential to read. Reading a chapter like http://www.repairfaq.org/samnew/tvfaq/tvsafg.htm is interesting in that everything that was applicable forty years ago is still applicable. People still get electrocuted. Warnings with regard to isolation transformers go past unheeded. In a workshop I used to oversee, computer systems were assembled and whilst the software was being loaded the supply had an uncanny knack of tripping out. Always the earth leakage would be the culprit. Often the system technicians would be just connecting mains cord to outlet when the entire mains supply would trip whereby all the systems which were loading software had to be restarted and reloaded. The workaround was to use an isolation transformer. Our electrical contractor told me the setup was illegal – makes one think where he was educated. A while later I discovered that he had no wireman’s licence. Just another bullshitter in the woods. Using the isolation transformer saved us thousands in the long run and no, we had no electrocutions. Repairfaq covers isolation transformers, sometimes a life saver when GFCIs just don’t cope. (caution: the two are not the same – read up on GFIC and isolation transformers if you are not sure). Quote from an article: “Finally, never assume anything without checking it out for yourself! Don’t take shortcuts!”

Repair Clinic – Arrogance beats knowledge hands down.

Many years back I worked for a company which employed service staff mainly self taught. What it did tell me is that arrogance had no bounds, the less one knew the more they thought they knew. A learned friend of mine with a computer degree (and BsC in Elect. Engineering) believed that we worked within a gray area – sitting between the digital ones and zeros and the interfaces, between firmware, hardware and software. Many computer technical self professed ‘boffins’ swap boards willy-nilly to find a solution. The entire industry is wrong – I don’t believe an A+ makes a good technician, aptitude and software knowledge is crucial. Just look at the motor industry – most ‘technicians’ do not know the electrical aspects which leads to part changers. The computer industry is just such a sector. Repairfaq is where the answer lies – grassroots reasoning.

A technician I worked with wanted to repair power supplies (switchers). I was apprehensive. Besides being an avid lover of the green stuff I felt he was over-confident. As a supervisor you will be held responsible for any harm or injury to your staff. Over-confidence is a killer and electricity at mains level will kill. The two don’t make good friends. Repairfaq will remind you of this. Highly qualified electrical engineers have been seriously injured by disregarding the safety aspects of any installation.

Repair Clinic – In conclusion

In conclusion, repairfaq is a no-fluff repository of articles going back many years. Well written by old hands. Whether a brand new audio system or TV receiver with brand new technology or a 1950’s TV or audio device, the techniques in which we repair these devices remains the same. Patience, safety and logic.To repair electronic equipment you will need a DVM, screwdrivers, side-cutters, pliers, socket/spanner set, cleaning materials and if you can afford it, an oscilloscope and bench power supply. Don’t forget a variac and if need be, an isolation transformer. Keep one hand in your pocket and somebody close by. And of course, lots of common sense.

For your own home repair clinic go to repairfaq.org.

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