Dangers and Safety considerations.

[lcaillo]

It has been suggested that I have not emphasized the dangers of servicing electronics enough in these forums. There are, obviously, many ways in which working with electronics can be hazardous, so this thread will be dedicated to discussing these dangers and proper ways to mitigate them.

One excellent place to start and a suggested read for EVERYONE is:

http://www.repairfaq.org/sam/safety.htm

[tonyvdb]

If I may,

One of the biggest dangers of working on electronics whether it be a TV, computer or receiver is that even though you have unplugged the power there are still very dangerous voltages present for even up to 4hrs after the incoming power has been removed.

Capacitors hold a very high voltage that can kill you. Capacitors are like a battery but will discharge all of its charge instantly if you touch the leads. Never assume that the voltage inside the hood is gone even after a short time.

[robbo266317]

Also be aware that consumer electronics are only meant to be opened by trained personel.
A lot of equipment isn't earthed either, simply relying on "double insulation" to meet local approval ratings.
I recently opened my Pioneer VSX710 and was amazed that the mains terminals & selector switch were not covered in any way. It would be very easy to inadvertantly come in contact with them if you weren't careful.

[lcaillo]

Good links to understand capacitor charging and discharging:

http://hyperphysics.phy-astr.gsu.edu...ic/capdis.html

http://www.repairfaq.org/sam/captest.htm#ctsdc



Generally, capacitors can be safely discharged using a resistor (to chassis ground or between legs) of between 10 and 100 ohms per volt for the rated voltage of the capacitor. This will avoid damage to the capacitor by discharging too rapidly, as well as prevent dangerous and uncontrolled arcing.

[cavchameleon]

lcaillo wrote:

Good links to understand capacitor charging and discharging:

http://hyperphysics.phy-astr.gsu.edu...ic/capdis.html

http://www.repairfaq.org/sam/captest.htm#ctsdc



Generally, capacitors can be safely discharged using a resistor (to chassis ground or between legs) of between 10 and 100 ohms per volt for the rated voltage of the capacitor. This will avoid damage to the capacitor by discharging too rapidly, as well as prevent dangerous and uncontrolled arcing.

Very good thread and advice. As far as discharging capacitors, it is a very well accepted practice in the custom stereo for auto industry as may have 'open' capacitors in the rage of 1 - 5 Farads (yes, that is correct, HUGE capacitors).

One other note I'd like to mention is that most equipment uses lead based solder (except for a few manufactures that are getting away from using lead). This can be a lot more toxic then one thinks, especially if handling it frequently. Venting of the work space to the outside (or through a system that's made to absorb fumes) should always be used - plus no eating while soldering until hands are washed. Heavy metals build up in the liver and are never release from the body. I've done my share of 'toxic' inhalation from a lot of past soldering (am very careful now).

Thanks for starting this thread! This should be noted in all DIY areas.

Ray

[lcaillo]

cavchameleon wrote:

Very good thread and advice. As far as discharging capacitors, it is a very well accepted practice in the custom stereo for auto industry as may have 'open' capacitors in the rage of 1 - 5 Farads (yes, that is correct, HUGE capacitors).

One other note I'd like to mention is that most equipment uses lead based solder (except for a few manufactures that are getting away from using lead). This can be a lot more toxic then one thinks, especially if handling it frequently. Venting of the work space to the outside (or through a system that's made to absorb fumes) should always be used - plus no eating while soldering until hands are washed. Heavy metals build up in the liver and are never release from the body. I've done my share of 'toxic' inhalation from a lot of past soldering (am very careful now).

Thanks for starting this thread! This should be noted in all DIY areas

Ray

Posted via Mobile Device

All new products use lead free solder. IME lead is far less of a hazard than suggested. I have worked with leader solder for 30 years and have been tested several times with negative results. I suggest reasonable care in using lead based solder, but it really is not great hazard. The fumes contain other hazardous substances but not lead.

[cavchameleon]

Icaillo,

I want to thank you so much for sharing a LOT of info in so many threads!!! I'm still reading some of them, very thoughtfully put together with great incite and care! Much appreciated.

Ray

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