How long for a TV to discharge before I can gut it?

[Dan_Turk]

I have a 2.5g marine tank with thriving corals, inverts, and a fish…a 5g tank does not scare me.

Heat will not be an issue, many things can be taken care of with fans and peltier coolers

thanks for the advice, everyone

[ftg]

Dan Turk: Here is a complete description of how to safely discharge a TV set. Note that it specifically rules out certain things that have mentioned in this thread so far.

If you do not have the experience, equipment and understanding to follow these directions under no circumstances should you attempt it.

As for leaving it unplugged, try 6 months. I’ve seen big charges coming from sets that have been unplugged at least a month.

[mks57]

@DougC

• And I’ve never ever ever ever heard that capacitors could significantly “recharge” themselves up, after being discharged.
  ~

One of the experiments that was performed in my basic electronics course was to attach a multimeter to an electrolytic capacitor and charge the capacitor with a DC power supply. After the capacitor was fully charged, the power supply was removed and the terminals on the capacitor were momentarily short-circuited, discharging the capacitor. As soon as the short was removed, you could see the measured voltage slowly rising on the multimeter. The instructor didn’t explain why it happened, he wanted to demonstrate that a capacitor can be a shock hazard even after it had been discharged if a bleeder resistor was not present or had failed open.

[DougC]

…After the capacitor was fully charged, the power supply was removed and the terminals on the capacitor were momentarily short-circuited, discharging the capacitor. As soon as the short was removed, you could see the measured voltage slowly rising on the multimeter… - mks57

• • • Shorting with just a simple conductor (or a screwdriver) is the wrong way to do it. If you do that, the voltage really only “bounces” back and forth between the plates of the capacitor, because there’s really not much resistance in the shorting wire. And your screwdriver (if you used that for shorting purposes) can end up slightly welded across a couple steel contacts. That is why I said that you should use a high-value resistor in the line you use for shorting, and leave the shorting line in place for a couple minutes. Just like those instructions that ftg linked to–they tell you to use a resistor in the shorting line, and to leave the resistant shorting line in place “for a few seconds”.
      ~

[mks57]

@DougC

• • • Shorting with just a simple conductor (or a screwdriver) is the wrong way to do it. If you do that, the voltage really only “bounces” back and forth between the plates of the capacitor, because there’s really not much resistance in the shorting wire. And your screwdriver (if you used that for shorting purposes) can end up slightly welded across a couple steel contacts. That is why I said that you should use a high-value resistor in the line you use for shorting, and leave the shorting line in place for a couple minutes. Just like those instructions that ftg linked to–they tell you to use a resistor in the shorting line, and to leave the resistant shorting line in place “for a few seconds”.
      ~

This was a classroom demonstration of a phenomenon and a hazard. It wasn’t supposed to be an example of an operational procedure.

[spingears]

@Dan Turk

20" flat screen that I want to gut and turn into an aquarium that plays DVDs.
How long should I leave it unplugged so I can be sure it’d be safe to operate on?

This is a CRT?
Don’t take chances. Discharge the CRT first with a grounded wire.
The phosphors on the inner face of the tube may prohibit the use as an aquarium as fish are senstitive to any toxic chemicals.