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Main => Monitor/Video Forum => Topic started by: phantompower on February 25, 2009, 01:56:53 pm

Title: Television Question
Post by: phantompower on February 25, 2009, 01:56:53 pm
Quote
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.
Title: Re: Television Question
Post by: SirPeale on March 01, 2009, 09:59:04 am
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.
Title: Re: Television Question
Post by: Ummon on March 03, 2009, 02:18:28 pm
Why would you leave it off, anyway. It was on there to begin with.
Title: Re: Television Question
Post by: qrz on March 07, 2009, 09:12:16 am
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
Title: Re: Television Question
Post by: Scucci on March 07, 2009, 09:32:52 am
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.
Title: Re: Television Question
Post by: DaOld Man on March 27, 2009, 10:04:14 pm
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?
Title: Re: Television Question
Post by: Level42 on April 07, 2009, 01:51:17 am
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.
Title: Re: Television Question
Post by: Kevin77 on April 12, 2009, 09:06:17 am
Make to attempt to skip high impulsive tension through a tube.
Title: Re: Television Question
Post by: Chandra on May 19, 2009, 10:00:35 pm
Quote
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.
Title: Re: Television Question
Post by: Chandra on May 19, 2009, 10:07:49 pm
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
Title: Re: Television Question
Post by: venkman on July 04, 2009, 05:50:59 pm

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!
Title: Re: Television Question
Post by: Nipedley on July 06, 2009, 04:32:52 pm
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.
Title: Re: Television Question
Post by: venkman on July 10, 2009, 08:10:26 am
 ;D ;D thanks!
Title: Re: Television Question
Post by: mvsfan on July 13, 2009, 08:18:04 pm
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.

Title: Re: Television Question
Post by: richms on July 15, 2009, 10:31:18 am

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.
Title: Re: Television Question
Post by: Beretta on July 16, 2009, 03:53:22 am
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.
Title: Re: Television Question
Post by: mvsfan on July 16, 2009, 12:05:47 pm
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.
Title: Re: Television Question
Post by: richms on July 24, 2009, 10:03:46 am
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.
Title: Re: Television Question
Post by: Brenry on August 18, 2009, 08:33:52 pm
you never know.  not discharging could lead to one of those freak accidents leaving you with SUPER POWERS muhahahahah ha ha   ha.
Title: Re: Television Question
Post by: mvsfan on September 09, 2009, 08:17:26 pm
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.

Title: Re: Television Question
Post by: Avinitlarge on October 15, 2009, 11:32:39 am
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
Title: Re: Television Question
Post by: kjeffery on November 03, 2009, 05:30:41 pm
my ghetto hv discharge kit

(http://i132.photobucket.com/albums/q10/nos_zc_36579/SDC11823.jpg)
Title: Re: Television Question
Post by: Avinitlarge on November 03, 2009, 05:58:47 pm
JESUS!!! Thats a bit OTT :o
Title: Re: Television Question
Post by: kjeffery on November 03, 2009, 09:45:05 pm
ha just what i had lying around
Title: Re: Television Question
Post by: danny_galaga on November 04, 2009, 06:53:37 am
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!
Title: Re: Television Question
Post by: ngranttx on February 13, 2010, 11:27:42 am
Unfortunately, the ppt link in the first post is dead :(

We are going to replace the U2000 in my die hard cabinet with a standard TV we have laying around. But will have to take it out of the case to fit it into the cabinet.  Anyone by chance have a copy of that ppt? 
Title: Re: Television Question
Post by: SirPeale on February 16, 2010, 11:36:05 am
Unfortunately, the ppt link in the first post is dead :(

We are going to replace the U2000 in my die hard cabinet with a standard TV we have laying around. But will have to take it out of the case to fit it into the cabinet.  Anyone by chance have a copy of that ppt? 

Do a Google search for "monitor discharge" there are many different examples of pretty much the same thing.

How are you going to interface the game to the TV?
Title: Re: Television Question
Post by: ngranttx on February 18, 2010, 10:02:37 am


Do a Google search for "monitor discharge" there are many different examples of pretty much the same thing.

How are you going to interface the game to the TV?

Thanks!  I did a google search and then started looking around on youtube.  Youtube, the new college...  Found a video, really very useful.  If anyone is interested the link is Discharging a TV CRT (http://www.youtube.com/watch?v=Iy7SnmQJffw#ws)


The TV has RCA in and my NVidia card has RCA out.  We have already connected it to the TV to test.  The front end looks ok and games look good (fired up a few and they looks nice.)  IMPOSSIBLE to read anything when in Ubuntu.  Might try connecting a monitor to it as well so I try to make some changes.  If anyone have any ideas on this I'm always open to suggestions.  (probably not the place to be asking this.)

Tonight, discharging and mounting TV in the arcade monitor brackets.  Going to use some of the TV hacks listed in the wiki :D
Title: Re: Television Question
Post by: tightwad on March 08, 2010, 12:06:56 am
Very helpful video!

I have a question regarding a TV i removed from it's case for size reasons...there is a loop of metal cable in the shape of a square 8 that went around the perimeter of the screen in the back, and then around the circuit board area as well.  What is this cable?  It is about 1/4" thick, and is connected to the circuit board/TV somehow as well...is this some sort of ground plane?
Title: Re: Television Question
Post by: MadmanDK on March 26, 2010, 05:25:24 am
I have a question regarding a TV i removed from it's case for size reasons...there is a loop of metal cable in the shape of a square 8 that went around the perimeter of the screen in the back, and then around the circuit board area as well.  What is this cable?  It is about 1/4" thick, and is connected to the circuit board/TV somehow as well...is this some sort of ground plane?
This is most likely the degaussing system.. Some monitors has a degauss button that de-magnitize the tube, so the electrons flows correctly. Other monitors degauss them selfes automaticly when they power up (some need to be turned off completely for a longer period before they do it)

You need to leave the cable around the monitor in your new setup, so you don't get any strange colour-faults e.g. because of un-shielded speakers
Title: Re: Television Question
Post by: reptileink on April 12, 2010, 11:04:15 am
After a high school friend of my wife died by "working on his tv", and reading this article, the 27" tv I just got will remain in it's case, and I will modify the WOOD instead....  :embarassed:

Title: Re: Television Question
Post by: SirPeale on April 12, 2010, 12:16:12 pm
After a high school friend of my wife died by "working on his tv", and reading this article, the 27" tv I just got will remain in it's case, and I will modify the WOOD instead....  :embarassed:



I'd be curious to hear the details of this.   The only things I can think of that would cause this would be discharging the anode - while it's still plugged in and ON.

I have a question regarding a TV i removed from it's case for size reasons...there is a loop of metal cable in the shape of a square 8 that went around the perimeter of the screen in the back, and then around the circuit board area as well.  What is this cable?  It is about 1/4" thick, and is connected to the circuit board/TV somehow as well...is this some sort of ground plane?

If it's metal cable (and not metal shielded with an insulation) wrapped around the tube (and connecting to the aquadag (the black coating on the back of the tube)) this is /very/ important  - even if it's a pain, find a way to incorporate it. 
Title: Re: Television Question
Post by: reptileink on April 12, 2010, 02:23:42 pm

I'd be curious to hear the details of this.   The only things I can think of that would cause this would be discharging the anode - while it's still plugged in and ON.

 

It was  a couple of years ago, and from what I was told, it was unplugged.....
Title: Re: Television Question
Post by: reptileink on April 15, 2010, 12:32:20 pm
What if the television has been sitting unplugged for over 6 months or so?? Still have a charge??
Title: Re: Television Question
Post by: SirPeale on April 15, 2010, 05:11:29 pm
What if the television has been sitting unplugged for over 6 months or so?? Still have a charge??

Sure.  The tube can hold a charge for years.  Just discharge it and move on.
Title: Re: Television Question
Post by: Zebidee on June 24, 2010, 10:57:39 pm
CRTs can kill someone if they have a weak heart and/or if they get shocked close to the heart.

I once got shocked by a tube while I was trying to mount it. I'd discharged it, but some charge had built up and it jumped to the soft skin on the inside of my arm. Lucky I didn't drop the whole thing. Hate to think what it would have been like if I hadn't discharge it.

Worst part was having to slide my arm up past the same anode cap-hole later, to tighten mounting bolts/nuts. All I could do was put on a heavy long-sleeved shirt and pray ....  :scared
Title: Re: Television Question
Post by: mvsfan on November 12, 2010, 07:25:05 pm
i used to use a screwdriver to check and see if a coil pack in a car was firing. Very dangerous. about every 10th time or so that the coil fires, the spark jumps right across the handle of the screwdriver and knocks you back off of it. for the curious, the reason that you dont get killed, is because a coil pack pulses for a fraction of a second and then turns off. the voltage hitting a spark plug is about 40KV, same as a monitor.

Monitors however dont turn the juice on and off every 1/4 second or so.

Using a regular screwdriver and a wire to discharge a monitor might not kill you today or even shock you, but it will eventually.

I do have a rather inexpensive solution however, for people who cant afford a high voltage probe.

Get an insulated linemens screwdriver like the guys at the power company use for working on the HV lines.

theyre not cheap for a screwdriver, but the whole thing except for the tip is insulated to 100KV. all you need to do is add a wire to it. it will run you about 35-40 bucks for one of these screwdrivers. Much cheaper, and just as safe as a high voltage probe.

Ive got one i use for discharging monitors, and another one with a spark plug boot, for checking coil packs.

Quote
How to discharge a monitor:

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

Title: Re: Television Question
Post by: srarcade on November 19, 2010, 09:48:42 pm
Just thought I would add my 2 cents here- I made a discharge tool much like most, a screw driver with a large clamp on it that has a 16 gauge wire with a spade lug on the end for easy grounding. (I didnt like how the alligator clips popped off stuff easily) However, for that extra insurance, at the screwdriver handle, I attached a 1 foot wooden handle! Psychologically it works too, I actually feel safe. I have yet to get a shock after performing 100s of discharges. I can also pop off the cap with this tool which allows me to immediately touch the annode cap leads to the frame to ground out the rest of the charge for the sure kill. Seems to work well so far, I'm still alive!

After the first few discharges, it becomes a easier process to do.
Title: Re: Television Question
Post by: lettuce on January 06, 2012, 02:47:02 pm
Thanks!  I did a google search and then started looking around on youtube.  Youtube, the new college...  Found a video, really very useful.  If anyone is interested the link is Discharging a TV CRT (http://www.youtube.com/watch?v=Iy7SnmQJffw#ws)


The TV has RCA in and my NVidia card has RCA out.  We have already connected it to the TV to test.  The front end looks ok and games look good (fired up a few and they looks nice.)  IMPOSSIBLE to read anything when in Ubuntu.  Might try connecting a monitor to it as well so I try to make some changes.  If anyone have any ideas on this I'm always open to suggestions.  (probably not the place to be asking this.)

Tonight, discharging and mounting TV in the arcade monitor brackets.  Going to use some of the TV hacks listed in the wiki :D

Jesus!, he committed the cardinal sin torwards the end of the vid, using two hands!!. Thats one way to kill youreslf right there, if the current travels up one arm arcoss your heart and then down the other arm. You should always hold one arm behind your back!!
Title: Re: Television Question
Post by: RejectedManiac on December 23, 2012, 11:49:40 am
If anyone is ever in the Pittsburgh Pa area I can remove the TV from the case etc for you for $15.