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I have asked questions on Stack Exchange. I have watched many videos on YouTube. I have asked professional TV repairmen. I get wildly different advice on the safety of opening my 1989 28" CRT TV.

The videos talk about keeping it unplugged (and "power-flushed" with the main power button before) for three days, using expensive special gloves and "grounding" the screen itself by using special tools and inserting a rod into a little rubber flapper thingie on top of the tube (once the chassis is opened) before you even think about going anywhere near the "death trap".

But the professional TV repair shop, who would have a financial incentive to tell me that it's super dangerous and I need to pay them to do it safely, just say: "Nah. No big deal at all. Just make sure it's been unplugged for a day before you open it and it'll all be fine."

How should I interpret this? Does the TV repair shop secretly wish for me to die from getting zapped? Are the YouTubers and Stack Exchangers "full of it"? Over-protective? Paranoid beyond reason?

I realize the irony of asking here about (partially) others (or possibly the same people) on here, but I have nowhere else to try.

I'm leaning toward power-cycling it, unplugging it, and then waiting a full three days before I unscrew the chassis, open it carefully, and, without touching anything with my hands, use my can of compressed air to blow the air off all the components inside, then put the chassis back on, and then clean up the dusty mess that has been created in the room since I don't dare to do this outside due to my back problems and the risk of rain. To me, this sounds perfectly sane, or rather, it would have sounded that way had I not heard all of this scary advice.

What am I supposed to think? Surely electricity cannot zap me through the air? And while I may be somewhat clumsy, I do believe I can keep my hands and arms from touching any part of the inner workings of the "death trap"...

L. Yerke
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    Sometimes it's because you never know if you're speaking to the lowest common denominator or not (and the person you're speaking to certainly wouldn't be able to judge themselves if they are). People have been seen to do really dumb things seemingly with zero thought invested. For example, hitting a ceramic component with a hammer, being surprised it broke and produced dust, and then coming on here afterwards to ask if the dust produced was toxic. "Surely electricity cannot zap me through the air?" It can if it's sufficiently high voltage. That's what arcing is, like tiny lightning. – DKNguyen Jun 07 '22 at 17:01
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    Does this answer your question? How dangerous is it for me and the TV to open up my CRT TV to dedust it with compressed air? – Solar Mike Jun 07 '22 at 17:12
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    I have worked on about 25 with no shocks , never waited as long as an hour. Although mostly B&W with lower voltage. Last one was a GE color , I think it had 25 KV somewhere. That was after GE had to redesign all their sets ( 1972 ?) because they were getting some X-ray leakage on some sets. – blacksmith37 Jun 07 '22 at 23:27
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    Why am I getting such conflicting safety advice regarding opening up and dedusting/servicing my CRT TV? ... because you are asking for an opinion – jsotola Jun 08 '22 at 00:00
  • It's like electricians that lock out a breaker and assume the contacts are live until they probe them. Even when they have the drawings and are familiar with the equipment. Safety first. If you are worrying more about the validity of the advice rather than what precautions to take, then you are missing the point of the advice. Assume it is live until tested. – StainlessSteelRat Jun 11 '22 at 05:29

2 Answers2

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It aint that bad.

Stay away from the metal clip that goes into the back/side of the CRT and anything that looks like a Cap on the board.

Tiger Guy
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1st of all I want to say that both of the ways may work. But the huge diference is the safe way and the correct way. In order for you to be able to do that de dusting you must to take in consideration few factors:

  1. The electronic boards and the components are old enough to have few tinny cracks already and still because nobody did not move away from position to be able to work good enough for you to have that TV up and running. So be aware about the fact that if you blow air with too much presure you may blow away a component or make some components to touch one with other. Those TV's from that generation use to have loads of components based almost entirly on analogic electronics. So in order to have a color TV on that time I can say that was almost 3 TV's in one (each who take care about a color) and few other components. Those TV's also was full of coils soldered and tunned and fixed with wax on top of the tunning screws. so also that may fly away. I can say that is a little bit extrem on 3 days for dry out all the power from the capacitors and the tube but, nothing is too much when is about safe. As specialists we use to go on the safe edge of the safe marge when we advice novice people how to deal with the technical issues because almost everyone will make errors or will try to short the terms. I evan hear the few guys who say something : If the specialist advise to keep it off for 1 day I think that will be ok after 4 hours. So we are saying 3 days in order for you to take at lease 1 day. About gloves and other protective PPE equipments. In this world are a lot of people who are dealing with the issues in different ways based on know-how, experience, life experience, rules setted in place, standard operating procedures and much more. Yes the safe way is to deal as a pro. use those gloves. but if are too expensive or you find that you do not have from where to get them on time you can slide away from that safe edge on regular medical gloves what are very cheap. the connection to the eart... I can say that is a good idea but sometimes not practical... Our bodies are working as antenna and capacitors. ESD is the term what you are looking for in order to deal with the electronic discharge. for very tinny period of time we can discharge thousends of volts from our static electrification to the components. During that time I can say that was not to many components very bady affected about this kind of ESD because evan the tinny transitors was much more strong than the transitors used today in our day to day life. but is a balance between safe and quick. So when those people from TV service center told you about the fact that you can open it after 1 day or so. I can say that they was pointing a fair time. Nobody can tell you for shure after how long time you will be safe, but all of us can tell thant no lower than 5 hours.

So:

  1. take extra care about the components. do not be rush because you may blow off the components or parts of them or so and not to many of them was labled by that time to know what you are looking for or if something was missing.
  2. the case if is made from plastic can be brittle or can easy crack during the fatigue or long time since was made so extra care also about how you will open that. easy starting with few turns for each screw and after that go one more round to each screw and so on untill you have completly removed all the scews. you may find other thinks what can keep the case on possition. such as evan the plastic around the cable, the scews from the back of antenna or so many other things.
  3. you need just an insulated cable to connect between the big cable what goes in the back upper (or 1/2 of distance of the tube ) in general it has a read color, and comes from the hi voltage transformer (black color on board) with a round plastic around (white or transparent) . you need to connect with a wire that to the chasee (metalic part around the motherboard or to the tube frame metalic stripp suport. this because the tube itself is acting also as a huge huge capacitor, so in order to play around this huge capcitor called catodic tube is better to be shure that you are connecting both of the terminals (the one of the red wire under a plastic cover on the tube) with the frame or the chasee. like a battery what is empty but can charge thousends of volts, for you to be sure that is nothig left in that battery in order to put you in danger is better to have connected both of the terminals of the "battery = capacitor = catodic tube" between them. so this I can say that is one of the most important part of the safe things what you will like to take in consideration in order to keep you safe. everytihig else is about how you will do your operations in order to do not damage also the TV.

VERY Important. !!! Do not forgot to remove this wire before to put back the lid !! Sometimes I am advicing people to put some tape on the scredrive what they use for the lid to keep it tight with this cable so when they will look for the scewdrive they will find it inside and will remember also to remove the wire. IF you forgot to remove the wire when you will plug in the TV and start a huge boom fire and the TV is dead forever ! (and this is not a joke, a lot of us back on those days happen to kill few TVs).

  1. Try to have a open window or so and to blow all the dust in one and the same directiion and to keep a vaccum cleaner near by in such a way as all the dust what will fly away from the tv to go inside of that vaccum cleaner so will not be a lot of dust full with bacterias in your house will be in the vaccum bag.

  2. If is possible ask for help as support. so ask the 2nd person for no way to put for any moment the hands on inside of the TV to touch or to pull anything. to let you to know if they see something or to made you aware about it in order to be as the pilots: pilot flying and the pilot monitoring. this person will be very userfoul with the vaccum cleaner but again ask to do not vaccume the components even if will be verry tempted.

  3. good luck and let us to know how did your operation was. Best regards, Somebody who does not know ;)

Florin - Ro
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