Adding "debug" electronics to electronics to quickly diagnose and repair.

Google is your friend, even if you're a USENET troll.

Search on "built in test" or "BIT" for the military/high-end usage, and "power on self test" or POST for PC usage.

And get a life.

quickly.

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inputs

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I think the engineers would never do this unless it would tend to make a fool of electronics experts. Very likely, bean counters would throw it out before it got that far. In my experience, it is business as usual to perform repairs in spite of the manufacturer rather than at the direction of the manufacturer unless you are somehow underwritten by the sales dept. Internal diagnostics schemes like these typically assist in manufacturing or sales and are only found in expensive high end equipment..

Many pieces of electronic equipment already have 'debug' modes. Almost everything from toasters to your car now have anything between 1 and 50 supervisory processor ICs in them, and it is a comparitively simple job for the programmer to build monitoring and testing routines into his code. The results of these may be accessible to the service engineer via several different routes, including some kind of 'standard' serial computer interface - RS232 or USB etc - or the unit's user display, or in its simplest form, by different flash sequences of the standby LED.

Yamaha AV amplifiers, for instance, have a very comprehensive monitoring and diagnostic tool built in, complete with memory to tell you what events have happened leading up to the failure. Your car also has very comprehensive monitoring of just about everything electrical and electronic on the car, and also most if not all of the electromechanical systems, again, complete with storage to tell the mechanic just exactly what went wrong. Most (decent makes of) TV sets have had the flashing LED type diagnostics for many years now.

Doing it by way of the system control processors is cheap for the manufacturers, as there is only a one-time investment in code writing overhead. No, or very minimal, additional hardware support, is needed.

Arfa

I was thinking about "simple" hardware like audio hardware (simple?).

Where there are many little simple components ?

Bye, Skybuck.

Yes but how usefull are current systems for actually repairing hardware ?

Time-wise too.

Repairman should be able to very quickly spot the defect and replace it...

I am even thinking about easy to remove and plug back components so that even non-eletronics experts could repair electronics by simply going to a store buying the necessary little components and simply stick them into place without any soldering... that would be cool ! ;)

Bye, Skybuck.

On 8/11/2009 1:01 PM Skybuck Flying spake thus:

You're assuming that manufacturers of such devices would actually want to make them easily repairable.

The opposite is in fact the case. Almost everything today is made to just be shitcanned and replaced if it stops working. Repair? What's that?

Hardware "repair" these days usually just means board swapping -- it's rather more expensive (in most cases) to perform component level troubleshooting/repair anymore, so few companies bother.

Ask your grandparents about their old tube radios some time... they occasionally came with replacement parts provided inside. I'm young enough that while I grew up seeing the ubiquitous "No user serviceable parts inside" disclaimer on everything I bought new (and would wonder, "Why do they even print that when it's the same for everything?"), one day I was astonished to come across an old radio of my mother's that said something like, "Serviceable parts inside: Two fuses, alginment tool, etc..."

Besides just the cost factor, another factor that led to electronics no being user serviceable include the vast improvement in reliability that come as IC manufacturing processes matured -- in many cases by the time the electronics in a widget fail, the widget will be obsolete anyway and the customer will just use the failure as a reason to upgrade to something newer/fancier. Indeed, other than "infant death" and "abuse," most remaining electronic failures are due to poor designs (see, e.g., the Xbox "ring of death" debacle... or Jan's post about his USB plugs) and not transistor/IC technology relability problems.

---Joel