A note about monitor discharging

[shardian]

To anyone afraid to do this, and thus living with monitors that need work: get over it and do it already! Now rest assured that this thread will quickly become a debate, with folks warning that you will die a horrible and painful death.

I was one of these big pansies for a long time. Finally I just got over it and did it. Guess what? I didn't die, didn't get zapped, or anything else. Matter of fact, it was just so anticlimatic that I had to juice up the monitor and try again just so I could see/hear a spark. Even that was entirely underwhelming.

So:
-Get a screwdriver with a good condition plastic handle.

-Clip on an alligator clip that holds securely, and clip the other end to the metal monitor frame. ( I personally used 2, because they aren't very beefy and I wanted a backup system.) No need to use a huge wire - just look at the size of the red anode wire - it isn't big either.

- stand on something non-conducting if working on concrete

- put one hand in your pocket

- slip that screwdriver under the cap a dew times and expect to not be impressed.

Proceed to fixing that dang monitor, cleaning up your cabinet, or whatever other good reason you have for removing the monitor!

[ChadTower]

Addition:  don't scratch up the tube coating around the anode opening.  If you do you're shortening the remaining life of that tube considerably.  It will start arcing around the anode cap if that coating gets too scratched up.  I've seen a couple that were really bad about that - it's a neat little spark show with the lights off.

[Kevin Mullins]

And not all monitors are so anticlimatic .... so don't ever get "comfortable".
When you do get a hold of a good one, you'll greatly appreciate taking the precautions.

[garnerb350]

shardian is right...just do it....

I now have a white streak thru my hair...but hey, the ladies like that...

[shardian]

And not all monitors are so anticlimatic .... so don't ever get "comfortable".
When you do get a hold of a good one, you'll greatly appreciate taking the precautions.

Precautions are fine. I observe all of the precautions necessary to ensure an uneventful discharge. I just think this procedure has been built up to epic proportions of difficulty. A level far above what it really demands.

[ChadTower]

I observe all of the precautions necessary to ensure an uneventful discharge.

...and I bet she is appreciative of that fact.

[drventure]

Rats, Chad, you beat me to it

[CheffoJeffo]

And not all monitors are so anticlimatic .... so don't ever get "comfortable".
When you do get a hold of a good one, you'll greatly appreciate taking the precautions.

Precautions are fine. I observe all of the precautions necessary to ensure an uneventful discharge. I just think this procedure has been built up to epic proportions of difficulty. A level far above what it really demands.

I agree with Kevin 100%.

At the same time, I agree with what Shardian is trying to say and am somewhat surprised that he apparently has never bothered to watch any of the videos of people actually discharging monitors so that he would know what to expect.

From the M/V forums here:

http://forum.arcadecontrols.com/index.php?topic=76567.0

This weekend I got my first significant "pop" from a WG4900 that I was working on ... and then a secondary "pop" *after* I had discharged and already removed the chassis. I've never gotten much reaction before, but still try to maintain a healthy respect.

Just don't get stupid when you do it and everything will be fine.

[AndyWarne]

I will repeat my usual comment on monitor discharge threads:

Only discharge a CRT if you are going to disconnect the CRT anode cap for any reason, for example to replace the chassis board or the flyback transformer.

There is no other situation in which you need to discharge a CRT. Removing a monitor from a cabinet is definitely no reason to discharge the CRT.

Andy

[FrizzleFried]

Biggest snap I've gotten was from an already discharged G07 tube... went to discharge again to put the anode wire back on and the spark jumped a good 1/2" to my tool with a fairly loud SNAP...

[Xiaou2]

 As an arcade tech,  I had to 're-juvenate'  a tube with a special machine. 

 It was a real pain.. because it had to be done several times.  Thus removal and
discharge many times over to see if the thing was decent or not.

 On the final cycle... I had thought I was finished... and started to plug the game
back in... but realized I needed to do something else.. and pulled the cord out fast
as hell.  The cord may have been in there for less than 1/4 of a second.. and so I figured
there couldnt have been much of a charge in there to worry about...

 I was less cautious...  and "POW"  a bolt jumped to my hand!   I was about 1.5 ft away
from a wall.   My body was jolted backwards. My elbow hit the wall at warp speed... so hard,  it nearly broke my elbow.   My back hit the center mounted wall bumper.  I felt like
I had been hit by a car.  My whole body ached in pains from the intense zap as well
as the wall impact.  My fingers smelled like they were burnt.  There were internal pains
running inside my arm.

 I was Extremely overcautious from that day on.   Discharge a monitor and let it sit for 10 min after the first discharge... and it still may have enough charge left to bolt you across the room.

 Im probably lucky to be typing this stuff.

 It can be done.  But it can also be dangerous.  Be careful, and never take them
lightly.

[Kevin Mullins]

And not all monitors are so anticlimatic .... so don't ever get "comfortable".
When you do get a hold of a good one, you'll greatly appreciate taking the precautions.

Precautions are fine. I observe all of the precautions necessary to ensure an uneventful discharge. I just think this procedure has been built up to epic proportions of difficulty. A level far above what it really demands.

Absolutely.
And the precautions are simple enough to follow that there shouldn't be such a dramatic fear placed upon it. IF you follow the precautions. If you don't, you're on your own and take your chances.

I personally have been promptly sat down on ---my bottom--- from a 25" tube. The wall behind me held me up long enough to slide down and take a seat for a bit. My kids who were not even in the same room heard the "crack" and the immediate "groan" (due to the fact that words would not physically come out) clearly enough that they came in to check what had happened.
It was totally my fault. I was in the process of repairing this chassis when I let myself get comfortable and out of sequence forgetting that it had just recently been turned on briefly after replacing the chassis to check for other issues.

Now I personally have a high tolerance for electric shocks, been bit many times from many sources, but still wouldn't recommend trying it.
All it takes is one time and it'll change someones respect for doing it properly and it's simple enough to do it safely.

Seems like a lot of people go "it didn't do much" or "it was just a little spark" .... but what they don't realize is the punch that can be behind that "little spark".

Fear it.... no. (heck, that usually causes the slipups)
Respect it and take the proper precautions.... yes.

Some monitors will bleed this voltage off to the chassis when powered down.
Some don't at all.
And the tube itself can be thought of as a very large capacitor...... it will hold that charge until something takes it away.

[CheffoJeffo]

Fortunately, I've never been bit by anything worse than the big filter cap on a G07, but I still get out the scrap piece of drywall to stand on, put my left hand in my pocket and use my discharging tool every time I pull an anode cap.

I pull the anode cap (and then discharge again) every time that I pull a monitor that isn't immediately going back into a machine. You don't need to discharge to pull a monitor, but it only makes sense to discharge if you are going to leave it lying around.

[Ummon]

I will repeat my usual comment on monitor discharge threads:

Only discharge a CRT if you are going to disconnect the CRT anode cap for any reason, for example to replace the chassis board or the flyback transformer.

There is no other situation in which you need to discharge a CRT. Removing a monitor from a cabinet is definitely no reason to discharge the CRT.

Andy

I'm bumping Andy's response, in particular for those who are afraid of de-casing TVs or other monitors. I've moved my multisync around tons of times. It's not in a case. No worries.

[CheffoJeffo]

I will repeat my usual comment on monitor discharge threads:

Only discharge a CRT if you are going to disconnect the CRT anode cap for any reason, for example to replace the chassis board or the flyback transformer.

There is no other situation in which you need to discharge a CRT. Removing a monitor from a cabinet is definitely no reason to discharge the CRT.

Andy

I'm bumping Andy's response, in particular for those who are afraid of de-casing TVs or other monitors. I've moved my multisync around tons of times. It's not in a case. No worries.

While I agree in principal with what you and Andy are saying (and I virtually never discharge *before* removing a monitor from a case or cabinet because it is safer to do it after), I would never leave an undischarged monitor lying around ... partly because I have kids and a wife who aren't as aware as I am, but also because it just makes sense.

[Jack Burton]

I'll add to this to keep one hand in your pocket at all times if you can when working on any sort of monitor.  I don't know about you guys, but for some reason when I'm working on something my left hand tends to drift to rest on top of it if I'm using my right hand for a task.  I melted the tips of my fingernails pretty good a while back while working on a tv on the floor.

that's another thing.  Don't work on any electrical device in an informal setting.  Don't just pull it out on the floor and go to town, or work on it inside the cab.  Make sure you have everything in an easy to get to position and you are away from anything that could harm you in a scenario like Xioau2 went through. 

[AndyWarne]

While I agree in principal with what you and Andy are saying (and I virtually never discharge *before* removing a monitor from a case or cabinet because it is safer to do it after), I would never leave an undischarged monitor lying around ... partly because I have kids and a wife who aren't as aware as I am, but also because it just makes sense.

Thats fair enough. This fits in with the analogy I used on another thread. Think of the CRT as a can of petrol. Perfectly safe to carry around when the cap is on (the anode cap in this case) but can be dangerous if opened.
No parts of the chassis or main board are connected to the final anode.

In fact discharging the CRT can lead to a false sense of security because the real danger lies in the power supply filter caps on the main board which can hold a lot of charge for a long time, especially if the monitor has certain types of faults which leave the power supply without any load. These caps are connected to large areas of the main PCB and completely exposed. The CRT anode voltage is not exposed anywhere normally.

[CheffoJeffo]

Best analogy (and I had been looking for one ... rejected the "loaded gun" as inappropriate) I have seen. 

Also explains nicely why I got bit by that G07 (I now know better).

Monitors are to be respected, not feared. I do encourage people to understand how they work before do even something as simple as a decasing.

I also second Jack Burton (Who ? Me! Jack Burton!)'s comments -- if you are going to work on a monitor, do so on a prepared work surface.

[FrizzleFried]

 As an arcade tech,  I had to 're-juvenate'  a tube with a special machine. 

 It was a real pain.. because it had to be done several times.  Thus removal and
discharge many times over to see if the thing was decent or not.

 On the final cycle... I had thought I was finished... and started to plug the game
back in... but realized I needed to do something else.. and pulled the cord out fast
as hell.  The cord may have been in there for less than 1/4 of a second.. and so I figured
there couldnt have been much of a charge in there to worry about...

 I was less cautious...  and "POW"  a bolt jumped to my hand!   I was about 1.5 ft away
from a wall.   My body was jolted backwards. My elbow hit the wall at warp speed... so hard,  it nearly broke my elbow.   My back hit the center mounted wall bumper.  I felt like
I had been hit by a car.  My whole body ached in pains from the intense zap as well
as the wall impact.  My fingers smelled like they were burnt.  There were internal pains
running inside my arm.

 I was Extremely overcautious from that day on.   Discharge a monitor and let it sit for 10 min after the first discharge... and it still may have enough charge left to bolt you across the room.

 Im probably lucky to be typing this stuff.

 It can be done.  But it can also be dangerous.  Be careful, and never take them
lightly.

Why were you removing the anode when you were rejuving?  You only need to discharge... no need to remove the wire.

[shardian]

I notice that you vets on here say that you have been zapped, but after you plugged in the monitor briefly and forgot to dicharge. My habit is to always touch the discharge tool to the anode every time before I bring anything near it. I 'discharged' the monitor maybe 20 times while fixing the anode clip. The tool is already hanging there, why not be safe and give it a quick probe?

My point: Your monitors weren't evil beings that thwarted your safety protocols - you just forgot your protocols. Yet you still word your stories in a way that puts this cloud over your warnings about monitors.

P.S. I learned a long time ago to use a screwdriver to discharge large chassis caps before working.

[shardian]

Yes, I had seen the videos. I even stood there and watched Wade discharge one of my monitors in person a few months back. I was still nervous as hell when I first discharged the LOOOONNNNG unpowered WG med res in that Sprint I picked up as a precaution. That's the whole point of this thread. Why in the hell was I that ridiculously nervous since I knew what to expect. The answer: the overblown fear mongering some people spew that no matter what you do safety wise - the evil monitor monster will still get you.

[CheffoJeffo]

I've got no argument with what shardian says about vets and not managing safety protocols properly. I was definitely overly scared the first time I discharged a monitor.

Discharging isn't scary ... forgetting to, on the other hand ...

[Ummon]

I will repeat my usual comment on monitor discharge threads:

Only discharge a CRT if you are going to disconnect the CRT anode cap for any reason, for example to replace the chassis board or the flyback transformer.

There is no other situation in which you need to discharge a CRT. Removing a monitor from a cabinet is definitely no reason to discharge the CRT.

Andy

I'm bumping Andy's response, in particular for those who are afraid of de-casing TVs or other monitors. I've moved my multisync around tons of times. It's not in a case. No worries.

While I agree in principal with what you and Andy are saying (and I virtually never discharge *before* removing a monitor from a case or cabinet because it is safer to do it after), I would never leave an undischarged monitor lying around ... partly because I have kids and a wife who aren't as aware as I am, but also because it just makes sense.

Similar to having firearms and gun safety, I'd lock - or in this case box - it up, and instruct those in the environment.

[astroone]

Youtube Has some Videos on discharging
http://www.youtube.com/results?search_type=&search_query=how+to+dischage+a+arcade+monitor&aq=f

[ahofle]

The tool is already hanging there, why not be safe and give it a quick probe?

I was definitely overly scared the first time I discharged...

Discharging isn't scary ... forgetting to, on the other hand ...

What is it with this hobby and all the sexual references?

[CheffoJeffo]

 

[Namco]

I think it's the way some people like to describe monitor discharging, or they are passing on the same fear, uncertainty and doubt that was passed onto them. Like when I asked my buddy if he's ever discharged a monitor and he proceeded to tell me about the time that he discharged one that was so powerful that the screwdriver was shot from his hand, flying across the room and impaled itself into the drywall handle deep. Or the story about a friend of his who once saw someone who decided to touch the anode cap of a still-charged monitor, blowing his thumb off completely.

But something tells me that all the parties involved weren't very bright (my friend included). 

[Ummon]

Sounds like they were illuminated greatly, to me. Alternatively, those sound like big fish stories, too.

[ChadTower]

My point: Your monitors weren't evil beings that thwarted your safety protocols - you just forgot your protocols. Yet you still word your stories in a way that puts this cloud over your warnings about monitors.

People writing advice aren't writing it for others who already know how to discharge.  We're writing it for people who don't know, and don't understand, where the teeth are.  Common sense is that if you don't know where the teeth are you don't stick your hand in until you do.  You know damn well that people don't read instructions, don't take advice, and absolutely don't read whole threads.  Given those facts about the people who are usually looking for instructions we write them in harsher language than is necessary.  Intelligent and prudent people do not need to be told the monitor is going to kill them.  Most people are neither intelligent nor prudent.

BTW, for the people who are talking about TVs and PC monitors... a lot of them are housing ground and not chassis ground.  They are not the same as an arcade monitor that is designed to run without a dedicated housing.  This is important and some of them are dangerous if you handle them the same way as an arcade monitor.  The challenge here is that in order to know which are which you have to already understand what you're doing.

[thecheat]

I used to work at an Apple authorized reseller doing repair work. We had one guy who would just grab the anode cap and pull it off the tube with his bare hands on the iMacs and Apple monitors. These more than likely would self-discharge when not powered but his method was to say the least, ballsy.

We of course had the right tool which was a length of 8 gauge wire with a clip on one end and an insulated probe with a solid wire exposed on the other. You ground to the chassis frame, sneak the tip under the anode cup, wait a second, and then remove it. Other places, not so well equipped, we would just use alligator clips and screwdrivers.

We would always store the analog boards with the anode caps secured to the metal chassis frame to ensure the flyback didn't store a charge.

I always hated working on monitors, not for the danger, but because replacing a part wouldn't always fix the problem on the first try and you'd have to tear the WHOLE thing down again.

[Namco]

This video was made the guts of two Wells Gardner k7000 monitors:
[youtube]o_PHLUvDZSg[/youtube]