Why Wait 10 Seconds Before Rebooting Your Router

[Golden]

We’ve all heard it before when troubleshooting a router: unplug your router, wait 10 seconds and plug it back in. More often than not, this fixes whatever problem we have. But why is that?

Why Tech Support Tells You To Wait 10 Seconds Before Rebooting Your Router | Lifehacker Australia

 

[x BlueRobot]

Thanks, I actually never know that

 

[jadinolf]

I knew it but never knew why.

 

[lehnerus2000]

Hidden Danger

The same thing applies for most electronics.
The time required to discharge the capacitors varies depending on the device (i.e. how much capacitance the device has).

Various devices can hold dangerous amounts of charge for a very long time (days or more):

• The old CRTs (the actual tube!)
• Power Supplies

You need to exercise caution when working on such devices and the best bet is to forcibly discharge them using a load.
Don't just short them out with a screwdriver.

If you don't know what you are doing, you should heed the warning labels.

 

[Faladu]

I'd like to hear how you clear a CRT, from zapping you dead, reason being, I may have a future need, thanks for the info heads up.

 

[oneskrewluse]

Discharging Filter Capacitors < all tube products are basically the same sort of speak

now to answer the question is that routers work off of d/c voltage and the caps hold voltage for a slight time which in turn causes them to not really turn off (if im working that clear enough) and if they dont discharge they dont reset

in addition some older modems and routers would bypass the voltage from the cable or phone line causing them not to reset also

so the motto is "when in doubt pull them out"

your pc is the same way ever notice a green light on the MB staying lit up when you unplug it for a few seconds?

 

[lehnerus2000]

Right Hand Rule

I'd like to hear how you clear a CRT, from zapping you dead, reason being, I may have a future need, thanks for the info heads up.

oneskrewluse's link (Discharging Filter Capacitors) provides some options, however I would use a much heavier duty resistor than 2 W, for discharging a CRT.

When I worked as an electronic technician, we had access to giant wire-wound variable resistors.
Something like that would be ideal.

The other big thing is the "Right Hand Rule".
Always use your right hand, when you are "poking" around electronic devices.

This can reduce the likelihood of electric current passing through your heart.
If your left foot/hand is the only path to ground, you'll still be in trouble though.

 

[Faladu]

Figures, I am left handed poker.... :roflmao:
Thanks for the follow up.

My follow up is, if just sliding out a CRT, at what point is the ZAP expected to be incoming? or what is touched that delivers it?

I have a bartop touchscreen game, to even get the CRT out for a replacement will be a major under taking and have never done it, plus I have an old Vectrex, still works, but at 31 years old, it can't be that long for this world, although rarely have it on, might have to go in there and rig it up to something else, I will not claim to be an electrician at all.

 

[bobafetthotmail]

I'd like to hear how you clear a CRT, from zapping you dead, reason being, I may have a future need, thanks for the info heads up.

Water bath. Will have to be dried throughly afterwards (2 big fans, left overnight), and you need to check that there aren't water-sensitive components first, but that's how I inspect PSUs.

Other general advice is wearing rubber boots and use a single arm (and doing this with a friend). This will prevent the current from going through your arms or discharge through your feet (passing through the heart in the process), and the friend will be there to rescue you in case of electrocution (knowing Basic Life Support procedures would be optimal for both, any first aid manual has them, if you saw at least one episode of Baywatch you should know them as well). They call it "the buddy system". Never do something dangerous alone. Remember the movies.
If you get a discharge with this setup it will be painful and you may lose sensitivity/movement of the finger/hand for a few minutes. Better than dying anyway.

I don't use rubber gloves as I drop enough stuff already, with gloves I'm less precise than a 90-year old with parkinson.

Btw, this comment in the article is priceless:

donks Guest
July 20, 2013 6:18 pm

Alternatively, if you can't wait 10 seconds just lick the capacitor to immediately discharge it into your tongue.

 

[Vertex]

I have used the 10-second trick on my MODEM as well many many times. I have learned the trick but never actually understood why. I just assumed that 10 seconds was just the right time for the unexplainable stuff inside there gets reset and that would hopefully correct the error once the power is put back on.

Now we know.

 

[Solarstarshines]

I figured as much because it has a few capacitors laid in there plus flash ram / battery to remember the passwords given to it

still good info though for people who need to know why this is

 

[ThrashZone]

Typical Power drain technic.
Although the normal power drain time is 30 to 45 seconds for best results.
For a router unplug and hold reset button for the same amount of time.

 

[A Guy]

I'd like to hear how you clear a CRT, from zapping you dead, reason being, I may have a future need, thanks for the info heads up.

This method will work. Generally the longer the power is removed, the more voltage that will dissipate. But a good CRT will retain voltage a long time. This method will result in a significant zap, but will not harm the CRT.

How to Discharge a CRT Monitor: 11 Steps - wikiHow

A Guy

 

[Lady Fitzgerald]

The same thing applies for most electronics.
The time required to discharge the capacitors varies depending on the device (i.e. how much capacitance the device has).

Various devices can hold dangerous amounts of charge for a very long time (days or more):

• The old CRTs (the actual tube!)
• Power Supplies

You need to exercise caution when working on such devices and the best bet is to forcibly discharge them using a load.
Don't just short them out with a screwdriver.

If you don't know what you are doing, you should heed the warning labels.

I used to cannibalize old TV chassis for parts when I was a kid (there was a TV repair shop on my way home from school and they would throw dead TVs out back; I suspect they depended on us kids to get rid of much of their trash for them). Since a chassis and CRT were too heavy to haul home on my bicycle, I would remove the CRT first. After one knocked me on my ample asset while removing the lead from the flyback coil, I learned to discharge them first, using a screwdriver with an insulated handle.

 

[Lady Fitzgerald]

...The other big thing is the "Right Hand Rule".
Always use your right hand, when you are "poking" around electronic devices...

...while keeping your left hand in your pocket. I heard the same rule.

 

[Lady Fitzgerald]

Figures, I am left handed poker.... :roflmao:
Thanks for the follow up.

My follow up is, if just sliding out a CRT, at what point is the ZAP expected to be incoming? or what is touched that delivers it?

I have a bartop touchscreen game, to even get the CRT out for a replacement will be a major under taking and have never done it, plus I have an old Vectrex, still works, but at 31 years old, it can't be that long for this world, although rarely have it on, might have to go in there and rig it up to something else, I will not claim to be an electrician at all.

If the charge doesn't bleed down on its own (the older ones didn't have a resistor in the circuit to bleed down the charge), it's the terminal for the wire that attaches to the side of the CRT. I always slipped a flat screwdriver blade under the boot on the connector to bleed it off (it often made an impressive flash). Keep in mind, I haven't touched the inside of a TV in 40 years.

 

[PaulGo]

The only thing capable of holding a charge either in modems, routers or TVs (including the older CRT TV and monitors) are capacitors. What makes the older CRT based sets so dangerous was that the CRT needed extremely high voltage to shoot an electron beam to the screen to illuminate the phosphors. Thus was accomplished by using a flyback transformer to raise the voltage level from the capacitors. Since the older CRT sets had large capacitors it could store a lot of charge which through the flyback transformer could give you quite a zap.

Flyback transformer - Wikipedia, the free encyclopedia

 

[Lady Fitzgerald]

The only thing capable of holding a charge either in modems, routers or TVs (including the older CRT TV and monitors) are capacitors. What makes the older CRT based sets so dangerous was that the CRT needed extremely high voltage to shoot an electron beam to the screen to illuminate the phosphors. Thus was accomplished by using a flyback transformer to raise the voltage level from the capacitors. Since the older CRT sets had large capacitors it could store a lot of charge which through the flyback transformer could give you quite a zap.

Flyback transformer - Wikipedia, the free encyclopedia

Heck, the CRT itself acted like a huge capacitor. And that zap could be dangerous!

 

[PaulGo]

The CRT cannot store voltage, but their is a connection on the side of the CRT (a thick wire) that comes from the flyback transformer which could give you a severe zap.

Edit: After doing some research I have found CRTs can indeed store some high voltage (because of the construction). Sorry:shock:

The Truth About CRTs and Shock Danger

 

[Indianatone]

The only thing capable of holding a charge either in modems, routers or TVs (including the older CRT TV and monitors) are capacitors. What makes the older CRT based sets so dangerous was that the CRT needed extremely high voltage to shoot an electron beam to the screen to illuminate the phosphors. Thus was accomplished by using a flyback transformer to raise the voltage level from the capacitors. Since the older CRT sets had large capacitors it could store a lot of charge which through the flyback transformer could give you quite a zap.

Flyback transformer - Wikipedia, the free encyclopedia

Heck, the CRT itself acted like a huge capacitor. And that zap could be dangerous!

Quite right Lady F. The CRT is a capacitor. The plates of the capacitor are the outside layer of graphite type material "dag" which is grounded to the chassis of the unit by bare metal wires under spring tension. The other plate is a metal covering on the inside of the crt which the EHT connects to via the connector from the flyback transformer with the glass as the insulator. The usual voltage is 25KV to 30KV but at a very low current generally not fatal. There is also a focus supply of around 4 to 5 KV and a screen voltage of 200 to 1000volts. The old TV sets from the 1930 used mains developed EHT (Extra High Tension) at 15A and these were widow makers. Microwaves are the same for the very same reason, high current and high voltage. Of course this technology is becoming obsolete. Heck DLP projection TV's, CRT projection TV, and LCD Projection TV's are headed the same way. Plasma TV's seem to be heading that way too due to their complication, high power consumption and weight compared to LED lit LCD's or Cold Cathode Lit LCD's which are much simpler to make and repair effectively making service of the units out of warranty cost prohibitive and causing TV technicians to lose their jobs like the 300+ from Best Buy last July. You are now likely if you have a unit purchased from BBY with a warranty and in home service to get a guy who fixes washing machines mostly as a lot of manufacturers don't even want anything 40" and below repaired it is exchange.