Television Question

[phantompower]

How to discharge a monitor:

See here for pictures and directions: http://www.arcadegames.net/sightsound/discharge.ppt

As this gentlemen points out, it isn't so bad if you pay attention!!!  DO NOT connect your alligator clip to anything other than the chassis of your monitor and the end of your screwdriver.  The ground in your outlet has absolutely nothing to do with your monitor do not ground the anode to anything other than the chassis of the monitor.

Just to hi-lite some points:
1. unplug the monitor from the power source
2. use a long handled screwdriver with a well insulated handle
3. keep the screwdriver side of the alligator clip as close to the end of the screwdriver (away from you)
4. keep one hand in your pocket
5. take off watches or rings and conductive things
6.be mindful of the chassis padawan--if you are touching it you could become the primary circuit path--NOT GOOD
7.  its always a good idea to pause a minute and discharge another time and another before removing the sucker cup (anode cap).

I left this vague so that you will go to the site and read how its done in its entirety.

Now that you have discharged the monitor, desolder the caps and replace with new ones that you ordered from Bob Roberts or elsewhere.  BE VERY OBSERVANT AS TO THE - AND + MARKINGS OF THE CAPS!!  If you get one backwards--poof!  it could also take other components with it.

I am getting ready to start my third cabinet and I am interested in using a television, but I need to remove it from the case so it fits my cab properly.  I have read quite a bit about properly discharging a television, but I am missing something fundamental...and have a question.

If I am not servicing my monitor and want to remove the casing from my television, is discharging necessary?  I was reading Martjin's thread about his cabinet and saw that he discharged his after he removed it from the case for mounting - I am just sure why the discharging is necessary - and [follow up question] after you discharge it, are you OK to leave the anode off the back and still operate the TV?

Thanks for helping to clarify this for me.

[SirPeale]

and [follow up question] after you discharge it, are you OK to leave the anode off the back and still operate the TV?

Only if you want the high voltage to shoot out of the anode and arc to everything around it.  It's 100% necessary.

[Ummon]

Why would you leave it off, anyway. It was on there to begin with.

[qrz]

if the crt has a substantial charge and using a screwdriver . be prepared for a loud SNAP.
many sets will bleed off the HV slowly, but still good to discharge a crt before handling.
no nasty surprises that way

i use the HV probe to discharge . use it anyway to read HV and it will discharge at a controlled rate,
rather than an abrupt short as with the screwdriver.

if u REALLY want to operate the set with the anode free .....(rarely needed in troubleshooting)

 IT MUST BE TERMINATED WITH A WELL INSULATED LOAD (HV probe again works nicely) AND LOAD
SECURELY CONNECTED TO CIRCUIT GROUND.

crt anode voltages are typically 25 - 30 kv
lower on the small sets , a bit higher on the big crts . anything above 32kv tends to generate X-ray radiation.
hence the presence of "HV shutdown/ Xray prot " circuits

qrz

[Scucci]

Here's a good tip for you... ALWAYS double check to make sure your grounding tool is getting good contact to the chassis. I have a setup that I've been using for a long time and didn't check to make sure it was getting a solid connection to ground.

So, I touched it to the contacts under the cap... and it picked me as a better ground. Normally my boots insulate me, but I was working on a cabaret and was on my knees... so, I dumped the charge instead of the grounding wire. I was holding pretty far back on the pliers I use, but that sucker can produce a pretty long arc.

I had to hold off on the soldering I was fixing to do because my hands were shaking pretty bad for about 10 mins or so... so, yeah... always make sure you have a good SOLID connection to ground.

[DaOld Man]

I have not tried to discharge a monitor before, but I am in no way an expert and dont pretend to be.
But I am an electrician, and it just seems to me that discharging the CRT directly to ground cant be good for the components.
Maybe the short is so quick that nothing is stressed, like capacitors or resistors.

Is there any component stress by shorting directly to ground? Is it possible to damage the parts?

[Level42]

The only thing you'd stress is the CRT itself because that's the "capacitor" you are discharging.

Now I know it's good for electrolytic caps to short them, especially the bigger one's, but I don't think we can see a CRT as an electrolytic cab.

However, I'd suggest to go with the resistor/HV probe method to be safe.

[Kevin77]

Make to attempt to skip high impulsive tension through a tube.

[Chandra]

How to discharge a monitor:

See here for pictures and directions: http://www.arcadegames.net/sightsound/discharge.ppt

As this gentlemen points out, it isn't so bad if you pay attention!!!  DO NOT connect your alligator clip to anything other than the chassis of your monitor and the end of your screwdriver.  The ground in your outlet has absolutely nothing to do with your monitor do not ground the anode to anything other than the chassis of the monitor.

Just to hi-lite some points:
1. unplug the monitor from the power source
2. use a long handled screwdriver with a well insulated handle
3. keep the screwdriver side of the alligator clip as close to the end of the screwdriver (away from you)
4. keep one hand in your pocket
5. take off watches or rings and conductive things
6.be mindful of the chassis padawan--if you are touching it you could become the primary circuit path--NOT GOOD
7.  its always a good idea to pause a minute and discharge another time and another before removing the sucker cup (anode cap).

I left this vague so that you will go to the site and read how its done in its entirety.

Now that you have discharged the monitor, desolder the caps and replace with new ones that you ordered from Bob Roberts or elsewhere.  BE VERY OBSERVANT AS TO THE - AND + MARKINGS OF THE CAPS!!  If you get one backwards--poof!  it could also take other components with it.

I am getting ready to start my third cabinet and I am interested in using a television, but I need to remove it from the case so it fits my cab properly.  I have read quite a bit about properly discharging a television, but I am missing something fundamental...and have a question.

If I am not servicing my monitor and want to remove the casing from my television, is discharging necessary?  I was reading Martjin's thread about his cabinet and saw that he discharged his after he removed it from the case for mounting - I am just sure why the discharging is necessary - and [follow up question] after you discharge it, are you OK to leave the anode off the back and still operate the TV?

Thanks for helping to clarify this for me.

[Chandra]

Can any one tell me is there any way to find the electrods of CRT tube, the heaters can be detect with multimeter, but other greed and cathodes. is there a web site with all these DATA of CRT Tubes. Thanks in Advance

[venkman]

If I am not servicing my monitor and want to remove the casing from my television, is discharging necessary? 

did anyone answer this question?

if, for example, i just want to take the plastic off so it fits in the cab.. would i NEED to discharge it?

i'd really rather not jam a screwdriver into the back of a monitor if i can avoid it!

[Nipedley]

The only time you NEED to discharge a tube is if you are removing the chassis from the tube (the circuit boards) otherwise no its not necessary. However if you are doing a lot of poking around with a screwdriver, you might want to anyway for safetys sake as it's a fairly big jolt. For just removing the case, I can't see that it would be a problem.

[venkman]

  thanks!

[mvsfan]

if the crt has a substantial charge and using a screwdriver . be prepared for a loud SNAP.
many sets will bleed off the HV slowly, but still good to discharge a crt before handling.
no nasty surprises that way

i use the HV probe to discharge . use it anyway to read HV and it will discharge at a controlled rate,
rather than an abrupt short as with the screwdriver.

if u REALLY want to operate the set with the anode free .....(rarely needed in troubleshooting)

 IT MUST BE TERMINATED WITH A WELL INSULATED LOAD (HV probe again works nicely) AND LOAD
SECURELY CONNECTED TO CIRCUIT GROUND.

crt anode voltages are typically 25 - 30 kv
lower on the small sets , a bit higher on the big crts . anything above 32kv tends to generate X-ray radiation.
hence the presence of "HV shutdown/ Xray prot " circuits

so thats why my monitor warns about Xray Radiation.

ive never thought about it really ive been working ar

qrz

Oh since someone mentioned getting the caps backwards heres a little info. If you ever see someone somewhere with a dead battery on their car who needs a jump, dont let them hook up the cables themselves even if they want to help.

i did this once and the guy on the other side crossed them over.

and poof their went both of our ECMS and my Instrument cluster.

250 bucks later, doing it myself, and a lot of junkyard crawling and my truck was running again.

[richms]

Oh since someone mentioned getting the caps backwards heres a little info. If you ever see someone somewhere with a dead battery on their car who needs a jump, dont let them hook up the cables themselves even if they want to help.

i did this once and the guy on the other side crossed them over.

and poof their went both of our ECMS and my Instrument cluster.

250 bucks later, doing it myself, and a lot of junkyard crawling and my truck was running again.

Thought I would chuck this in here too - dont disconnect the leads with the donor car running, if you do then the load shed of the dead battery in the other car will cause another spike in the donor car. Really you dont want the donor car running at all when you crank the dead car for the same reason. A BMW manual said to turn the lights and heater motor and everything else in the donor car on when jumping but when I tried that on my car I ended up with 2 blown headlight bulbs and my amp going into protect mode till I pulled its fuse out and reinserted it.

[Beretta]

not to get to far off the subject but for jumping cars i suggest you get a jump pack, can be had for 30-40 bucks, these little puppies are simple.. and not much more then a smaller lead acid battery with built in jumper cables.. they work a treat.. just remember to let it charge back up after jumping a car..

my brother used my jump pack to jump like 3 cars and as soon as the car would star he'ed remove the jump pack never letting it get a chance to recharge.. when he went to jump a 4th car it was dead.

[mvsfan]

yes they should really build in some kind of protection circuit for this in anticipation of joe six pack trying to jump it but they dont.

[richms]

Those jump packs are wortheless IME - a 7ah alarm battery with a handle and useless meter and light on it.

May help with a flat battery, but a dead one no way... - put it on and it will dump into the dead battery bringing it up a little and then nothing left.

[Brenry]

you never know.  not discharging could lead to one of those freak accidents leaving you with SUPER POWERS muhahahahah ha ha   ha.

[mvsfan]

i dont like the idea of cutting yourself short.

ive got a fluke 40000v HV probe i happened across a while back.

anyway ive heard about crts recharging and coming back alive to bite you like the zombies in dawn of the dead well sorta.

but anyway this fluke has just killed dead every crt or zombie ive stuck it into with no residual voltage and no spark or bite.

[Avinitlarge]

I have discharged a tube trough my body twice. Belive me, It hurts, ALOT.
The 1st time I stuck the screw driver under the EHT cap, I was touching the shaft of the screw driver. The 2nd time I cut straight through the EHT lead just after turning the set off.

If I am doing any work on a TV or monitor, I always discharge the tube to be on the safe side

[kjeffery]

my ghetto hv discharge kit

[Avinitlarge]

JESUS!!! Thats a bit OTT

[kjeffery]

ha just what i had lying around

[danny_galaga]

The only thing you'd stress is the CRT itself because that's the "capacitor" you are discharging.

Now I know it's good for electrolytic caps to short them, especially the bigger one's, but I don't think we can see a CRT as an electrolytic cab.

However, I'd suggest to go with the resistor/HV probe method to be safe.

yes ,you are very right ,i agree with you more.

:)hehe!a interesting post!

haha!that is awesome!