TVs can die from excessive humidity?!
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TVs can die from excessive humidity?!
my outbuilding i've been renovating to be used as an office and work shop has a TV with an extra DTV Converter hooked to it. it rained over 2" last night and the humidity was over 95% inside it, not leaking but just the moisture in the air. i turned on the set, a General Electric 19" color TV made in 1984, on, and while i was listening to noise (why i got it, terrible color anyways great for a distraction though) the TV up and started going bzzzzt! and i immediately unplugged the set. a little smoke billowed and i thought it was dead. after it cooled down i tried plugging it back in and hit POWER. and i heard high voltage and sound, channel LED display says '03' and then bzzzzzzzzz! and more smoke. i then took it apart after pulling the plug again expecting to see a fried yoke, but instead it wasn't the catastrophic failure i expected. i think it was the humidity since what happened was an arcing CRT Anode. no real damage other than a little burning of the anode suction cup. am i correct in assuming i can discharge the CRT the proper way, clean it all up and try it again in normal humidity? the TV will still power on but with it apart i can see a spark jumping from the anode cap and hitting ground anywhere in the set. but obviously it's fixable? i get no picture but that may be due to insufficient voltage to the CRT due to it literally discharging from the cap.
Last edited by DTVuser2009; 06-04-2009 at 04:27 PM.
Certainly humidity can damage any electronic item. I was warned about that years ago. Excessive heat in one part of my house killed my hard drive on the computer a couple of years ago even. I'm just real aware of humidity/heat issues as a result. I feel your pain! Been there, done that!
It sounds like there was dust on the cap, since where there is static, there is dust. Then the dust absorbed water from the air. Solids when dissolved in water form ions. water actually is a good insulator until something is dissolved in it. And all water has stuff dissolved in it. In particular the water that formed on your TV anode. So it was a conductor, dew with dust in it. Seen it a hundred times before.
Originally Posted by DTVuser2009
If you know how to ground the tube and remove the anode, you can clean everything, by dusting. Then they used to sell this stuff you could goop on that was non conductive. It would keep it from happening again.
Also note that burnt rubber on the anode cap becomes conductive. So if you have to remove a little of the cap, do it. Then goop on than anode stuff, but I can't remember what it's called anymore.
I've had many a computer die on me in this room, the room get pretty warm, I thought I was using the wrong wattage power supply.
Originally Posted by Orrymain
When I put in a Peltier heat pump cooler in one of the computers, it worked great, until the CPU anchor tabs got broken off since that Peltier added a bit too much thickness between the CPU and heatsink, giving extra force against the tabs. Drat. Wish they were made of non-conductive polycarbonate instead of flimsy ABS plastic.
A note to the "novice" members. Be EXTREMELY careful discharging the flyback transformer anode at the picture tube. 30-40 thousand volts is an eye-opening experence. There's high-voltage discharge probes available in electonic supply stores or can be purchased online.
I just made mine from a long bladed screwdriver and a piece of heavily insulated wire. Tape the wire to the screwdriver with electical tape and ground the other end of the wire to the HOT ground. Then carefully slide the screwdriver between the anode cap and the tube holding the handle of the screwdriver.. Zap the anode is dicharged. Always use the "one hand rule".
And the one hand is best your right hand. Even if you are left handed.
Originally Posted by ShowMeRon
If you use both hands the discharge will pass by your heart , one arm and out the other.
Also though if your feet are grounded and you use your left hand the discharge can pass through your left arm by your heart to your feet.
So ONE HAND RULE and make it your right hand.
Piggie I think that non-conductive goop you're referring to is called "dielectric grease"
Aaron62 we are discussing safe ways to discharge high voltage in a CRT to fix an arcing anode in hope of reviving a tv
Last edited by DTVuser2009; 06-05-2009 at 11:56 AM.
Yup, you let the magic smoke out of it. If any electronic gets wet, the only thing you can do is leave it to dry out completely, turn it on, and pray to God that it still works. Although, if water causes an LCD TV to fry, the colors will invert. As far as I know though, there is no way to reverse it.
Nope i didn't let the magic smoke out, the 'smoke' that was burning from it was just the cooking CRT high voltage anode. it didn't destroy anything on the main PC board in the set. in fact it will still turn on but you'll witness a literal lightning bolt arc from the anode from 'leaky' voltage causing the CRT to not get high voltage which = no picture and the smoke from excessive arcing. i only need to discharge the high voltage, remove and clean the anode and hope when it is put back together it will still work. i know how to work on TVs i just don't like to. this is why. discharging the set makes a loud BANG! and i get scared every time.
I would lean toward dust build up in the TV before I would consider humidity being a problem. I would make sure you blow the dust out of it thoroughly and try it again. Corrosion would be a more common problem relating to humidity.
The Electronic Industry
In the electronic industry, printed wirings get corroded due to presence of high humidity. Transistors
may break down or suffer a decrease in longetivity and the uniform growth of crystals is unachievable.
In fact i am thinking of cleaning it FIRST and trying it again. if it still arcs (i will test it while the case if open) i'll then go farther. but to clean an anode i will still have to discharge it. i just get scared to since it's a bright flash and loud. that and we're talking 40KV+ here. i know i wear gloves and don't stand in water but then i'm afraid of walking into an old house and touching wires even when i know the utilities are already disconnected. for some reason i expect to get zapped lol. I have been zapped by 220V low amp and also the common 10KVDC shock from an ignition coil will open all the curse words as i hold my then numb arm. i hate electricity but i like to fix things so it's kinda a bittersweet pride to fix a TV. i prefer it more when the fuse is blown and that's all it takes.
Actually i was thinking of using aligator clips to clip one side of to the anode and another one to a switch so i can do it at a distance back from the TV set. that way all i do is throw the switch to ground and the bang happens about 50ft back. safer that way. i mean we're basically shorting the voltage to a ground. no reason i can't make it as safe and use a switch inline to make the connection, assuming that hooking the one wire to the anode doesn't literally light up my life, as electricity has to have a ground path first. i've arc welded flat blade screwdrivers before with this and it's scary enough that i don't like to keep doing it lol
Make sure the switch is rated for the voltage spike.
Originally Posted by DTVuser2009
I just looked it up online and i'll try it later tonight. i will first try again to turn the TV on and see what happens. if it works, great. if not, discharge/cleanup. maybe there won't be that much to discharge if it was leaking enough to arc around the set like it was so it may have lost almost all it's spark in doing so. but i'm not holding my breath on that luck. i paid $15 on the TV and it's a thrift store model so it was final sale only so i'm NOT going to toss a TV that i paid that much for and got one day's use out of. btw this isn't the Curtis Mathes that set is still working, this is a G.E. 19" TV that i use in the workshop as a distraction as i work.
What i think was happening was a corona discharge. i.e., sizzling under the cap. may be only when the humidity was high and i may not have to do anything but wait for the air to dry out.
Last edited by DTVuser2009; 06-05-2009 at 05:37 PM.
I discharged the CRT (wasn't much there at all oddly enough) and removed the anode, and cleaned it and the area on the tube where it connects, and put it all back together to see if it works.
IT WORKS!!!! BUT, i think i will need some di-electric grease it seems to still have some staticy sound from the anode area suggesting there's still some arcing which means either 1) the humidity is still too high for the set or 2) it needs some more work and non-conductive grease. but for now it is working and i turned it off for the time being so i can fix it right.
Ha! I've been there. I remember my Grandpa's TV would make an ungodly racket when you changed the volume, and he changed it all the time. Those were some good times, until he let the smoke out.
Yeah i know, probably will get a louder pop when i do that since it think most of the HV was discharged through the arcing in that mess before. i tried three different attempts since i didn't get much at all.
The TV has a 'service manual' right inside the cover, accessible from inside the set only. it was handy with finding out how much HV the set has. i was surprised. it says only 26.5KV HV with raster. funny, i have seen 40KV quite common but this is an old set so whatever, less is better IMO.
When it first did this it was actually smoking bad after the tube went blank and sizzling from inside the set making me think it was done for; i figured the yoke was shorting out. when i took it apart (i like to find out what caused the set to die before throwing it out as a rule) to diagnose it i found a cooked anode cap but not destroyed. so i was happy that was all it was. then i asked here and also got some information on the symptoms to find that it was possible that dust was on it (tons of it, apparently this TV was owned by a smoker it had tar all inside it too) and condensate formed on it providing a ground path for the HV. in fact, when i removed the anode itself i found moisture on the underside of the cap. yep, that was a problem.
Non-conductive grease will add to my confidence later but for now the set is not in use to prevent more problems from happening.
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