How to check for high voltage and discharge

[icantthinkofaname211]

i actually cut that red cord there without any knowledge of knowing about the discharge, would i still need to discharge the television with that cord already cut? and if so would i have to do something differently?

[MrJeremy313]

omg 4real dude i did know that thank u telling us Not have great day say with the job doing u be doing well when turn 65 with 5.00 hr job working on old tv's

[TheDANIELCAMPBELL]

i have 2 rca crt tvs one works one trys to come on and goes off what can i do to get it to work

[chrisstv1979]

@TheDANIELCAMPBELL upload a video and explain the problem. Need model# size year of manufacture, give as many details as possible. The more the better.

[djkc2411]

You're worried about someone else plugging in the tv or "outside distractions" causing a "recipe for disaster".. Folks, THIS VIDEO is a RECIPE FOR DISASTER!!!!!

[djkc2411]

This video is a TERRIBLE PRESENTATION by some guy who NEEDS TO DRINK A DAMN GLASS OF WATER before making his "PROFESSIONAL" video. THis is some kid who doesn't know how to freakin COMMUNICATE!!! He doesn't give you any general info at first, or preparation on ANYTHING HE'S F'ing TALKING about. TERRIBLE INSTRUCIONAL VIDEO!! This is bout to do more harm than education. TAKE THIS VIDEO DOWN!!!

[gerardo0921]

video player is good equipment for alignment fist align the def.yoke for hor. vert. positioning 2nd the convergence for good picture

[GLaDOS488]

the rubber cap broke on my tv

[peugteobike]

I heard picture tube can operate between 20,000 to 25,000 volts . keep this in mind.there is conductive coatings inside and outside the tube

[morrismagic08]

In the 1990's before i knew what a HT lead was i just pulled the damn thing off! I remember hearing a loud CRACK! I went f***ing blind for two minuits,had to sit down.When i gathered myself i felt unbelievable pain down my neck,left arm,hips,left leg and it felt like someone hit me on the toes with a lump hammer! My wrist and finger were stiff where my watch and ring was too. I'll never forget that day. What a rush!

[matholton]

@morrismagic08 That sounds so damn scary. Way back in the early 90's, I was fiddling around with a huge old CRT - just checking it out, looking for lose wires or something (I had to whack the set to keep the picture and wondered if it was something I could fix). I brushed my arm against something in there and got the biggest damn shock. Not as bad as your story but it's made me extra wary of high-voltages ever since. Horrible.

[morrismagic08]

@matholton I approach all electrics with caution since that day but it don't stop me getting a shock from time to time! I even got a jolt from a camera flash once! It felt like a big needle got stabbed in my finger.lol..

[whiskeyify]

@matholton I don't know how that happened...I've touched the high voltage lead many times and nothing happened. I'm not saying it's perfectly safe but when you're working on a set many times you will come in contact with it. Maybe you touched the yoke coil ?

I've 62 years old and have been working on sets for many years.

[summer3245]

hi i have a 1998 rca big screem tv.when i turn it on i see the light up for a second then i can only hear it no picture.is the flyback transformer make the picture show.if not do you have more video on how to make the picture show thanks wanda

[NOLIMIT69NOLIMIT2000]

You failed to tell people that they should discharge the crt before hooking it back up seeing that many of them have the tendency to build up a charge again while they are sitting.

[MIKON8ERISBACK]

I have a Sharp "Linytron Plus" color TV, manufactured August, 1983. I need to know what some small dials located behind the neck of the CRT are for. I just cleaned out the entire thing using frost-spraying computer duster, and Clorox wipes. I think they may have something to do with the vertical and horizontal alignment, and I need help on how to adjust them without being electrocuted.

I read something about wearing rubber shoes and keeping one hand in a pocket.

[chrisstv1979]

@MIKON8ERISBACK My advice it to you: Do not touch any of the controls on the CRT. These controls are for color and convergance. Its important not to touch these because once you do its very difficult to bring the TV back to normal. Both convergance and color are not an easy thing to set up with out using proper equipment and even if you do the TV will never be the same again.

[MIKON8ERISBACK]

@chrisstv1979 The reason I asked is because I may have misaligned them when I was cleaning the circuit boards.

[kakstis1]

@chrisstv1979 If you do, mark where you started so you can always go back. If you dont, then you will regret it.

[whiskeyify]

@chrisstv1979 That's not true that the set will never be the same again, I used to adjust a lot of them. Customers would tell me their tv picture looked better when they came to pick up their set. I use a black and white picture, and the secret is to just turn the magnetic rings just a little bit at time.. but I agree it's best not for most newbies to touch these settings.

[VideoGuy84]

@MIKON8ERISBACK chrisstv1979 speaks the truth...I learned the hard way. Those little 'knobs', at least in the case of my little 90s era RCA, control what I believe is know as the 'grayscale'. Mess with them and your TV will probably never show the correct color again. I even took mine to a local repair shop (after I messed it up) and he did not have equipment to fix. I'm not a TV expert by any means but its my understanding that pretty much anything on the CRT neck you just should not mess with.

[MIKON8ERISBACK]

@VideoGuy84 I touched them by accident. If I attempt to restore them, do I need shielding from electric current? I know how much juice the components near the CRT pack: FLESH COOKING AMPERAGE!

[VideoGuy84]

@MIKON8ERISBACK Well I'm no expert (and I'm sure I'll catch some flack for this) but what I did to attempt to correct mine was place it side by side to a set with known good color, feed them the same picture, and then adjusted to try to get the best match. I just used a screwdriver with a thick plastic handle and was careful to only work with one hand, and to NOT short out anything else with the screwdriver. Google "grayscale adjustment" to get an idea of just what an undertaking this is.

[VideoGuy84]

@VideoGuy84 This just applies to just the grayscale, or the level of the individual red green and blue guns. But when it comes to convergence (the little white 'tabs' on the neck of the CRT) I've never messed with any of that nor do I ever plan to...I'll leave that to the pros. From what I understand those are pretty solid, it would take dropping the set or smacking the neck/yoke with something like a hammer to knock them out of alignment...I don't think cleaning wipes would do it.

[kakstis1]

@MIKON8ERISBACK You more than likely detuned the whole board when you sprayed that. You should always isolate what you are spraying with tissue or something so you dont ruin other components.

[MIKON8ERISBACK]

@kakstis1 What does "de tuned" mean? I hope it doesn't refer to permanent damage.

[Ponnybit]

man im so scared... like here's my problem, i bought an arcade machine, really HUGE machine, i EVEN had to take the doors from my living room and study so i could pass the machine trough... now when i was assembling, testing it, the circuit board for the crt burned a cap now i want to take the circuit board out to repair it, or send it to someone for repair but i know i have to discharge it first but im awfully scared... there's no way im gonna ship 120kilo of wood for a circuit board repair...

[Ponnybit]

@MrHammadmossop1988 too late, i've alredy replaced it, but i blew it...

that litle board you connect to the back of the tube, without noticing it, when removing it, i cracked the begining of the crt tube, now i have no ideia what to do, it's really small, like a hair, but i dont know why, the board doesn't even turn on, there's two lights, a red and a green. both of them are off, the fuse is ok, and i've replace the damaged resistance (it wasn't a cap after all)

is there anything i can do?trash?

[whiskeyify]

first started working on tv's back in 1966 in high school electronics class.

I got a shock off a tube one time, did not hurt me. I saw my teacher one time get shocked by the high voltage in a set while it was powered on.. It did not hurt him.

Of course you should always be careful and not take chances with high voltage.

It could cause an injury.

[zker666]

high voltage is very dangerous, but the CRT only holds a voltage of about 20kV+, and a capacitance of only 0.01 microfarads, which is only 2 joules, which will get your attention, you might pee down your leg a little, but it is far from lethal

[chrisstv1979]

@21hammadmossop The HV can only be discharged by u. Using a HV test prove or using a flat blade screw driver shoved under the cap and use the WIDE BLACE OF THE CORD TO DISCHARGE IT. BE CAREFUL WHEN DOING THIS!!!  DO NOT USE THE NARROW BLADE ON THE PLUG OR YOU WILL DAMAGE THE TV!!!!!!!!

[chrisstv1979]

@21hammadmossop The high voltage is very dangerous. Touching that arc will cause severe burns and can even kill you. Be careful around the CRT while the TV is on. I am a professional, I have got over 11 years experance working on TVs.

[whiskeyify]

@chrisstv1979 have never seen or heard of a tv repair man getting burned or killed by the high voltage in a TV set. Have been working on sets for many years, I'm 60 years old.

My teacher one time got shocked by the high voltage in a set one time, he jumped around a lot but was not hurt by it. Of course I still follow the safety rules.

The older sets the high voltage could get very high, but now there is protection build in to regulate the high voltage.

[guitarbyous]

@whiskeyify

Is this the solution to popping sounds that comes from a tube tv?

[whiskeyify]

@guitarbyous no if you have popping sounds when the set is on it could be the cap is loose or there is dust there. Make sure the cap is tight by tugging on it.

If there is a lot of dust on the tube then clean it. Sometimes dust can cause arcing.

[guitarbyous]

@whiskeyify

If my tube has been shut off and unplugged for a few hours is it safe for me to just dust it?

[whiskeyify]

@guitarbyous yes, in fact when working on a set that is on I have bumped and touched that red high voltage wire many times. Sometimes you are trying to make some adjustments and touch the high voltage wire. But I have never gotten a shock.

But turn the set off and uplug it just to be extra safe.

[troy2062]

@chrisstv1979

The HV of a CRT is nowhere near as hazardous as many would claim. Ending up as the ground of a discharge is not particularly pleasant, however it will not cause you any harm.

It is the low-voltage capacitors which you need to worry about. These will not discharge in the form of a pulse and genuinely can be fatal.

[kakstis1]

@troy2062 so a black and white crt has 17kV running through it. That would be considered fatal. A color has more.

[troy2062]

@kakstis1

The voltage may be high, however the current is very low (generally around 25-30mA) and the frequency is very high. Unless you have a rather severe heart condition, a HV discharge will not harm you.

[whiskeyify]

@chrisstv1979 FYI guys you can use a wire attached to a screwdriver and push it under the cap. discharge it and then wait a minute or so because it will tend to charge up again. Anyway I got a shock one time from a tube...I was lifting a tv into the car. It was not all that bad...but always use caution.

[chrisstv1979]

@21hammadmossop When u discharge the HV(high voltage) anode it does not hurt the CRT. If you punch a hole in the place where the anode goes, then you will damage the CRT. If you snap the CRT neck then you will also damage the CRT, but not discharging the anode. The anode will be recharged once the TV is turned on again and the flyback applys power to the anode.It is very dangerous to work around a live CRT. Its important to know what u r doing. The TV prodeces thousands of volts to the CRT.

[dwarfer777]

its worth pointing out that UK users should be able to keep it plugged in (but turned off at the wall) because we have an earth wire.

americans! full of themselvs

[jugghead82]

Hey I have a symphonic 27 inch TV, Ive been having alittle problem with it with hortizonal white lines in the top of the screen I was told it had something to do with the power capacitors. I would like to know how long will it take if I unplug the TV before I can work on it dont have a meter.

[chrisstv1979]

@jugghead82 Replace all caps in the vertical section and also replace the vertical IC.

[guzguz21]

Is there any safer way to discharge a computer monitor? I don't want to do what you did so I was wondering that maybe if I leave the monitor unplugged for a month or two it will self discharge?

[wobblyman2000]

could you please tell me the name of the stuff to remake a seal when you put that cap back on i have a set that does not have a great seal and is arcing

[chrisstv1979]

@wobblyman2000 Use silicone sealer from your local hardwarestore to put around the cap to keep it from arcing

[chrisstv1979]

Ok to everyone, I understand that you might not be able to see when I unplug the set. The set gets unplugged before I discharge the High Voltage wire. The only time the set is on is for the High Voltage Check.

[zukismooth]

I have a question:

Please correct me if I'm wrong, but at ~1:24 you turn the tv on. It's plugged in at the time. Is it on and connected the whole time it's discharging?

I didn't see at what point you disconnected the TV from the outlet but I'm sure it was at some point before you put your hand on rubber cap, but I'm not sure when.

Thanks in advance!

[donnaloveschris1]

I loved your video and i understand everything u say about the tv sets.

[kevykev38]

Thanks That actually helps. A friend of mine got seriously hurt from this. He liked to dabble with electronics and figured ..Hey what the heck i will attempt to fix my tv... He's ok now ..But it knocked him out. Sorry for being soo harsh with this matter.