Monitor Safety question

[HeadRusch]

------ INTRODUCTION HEADER BY SAINT -------

The information in this thread is of an extremely high technical level and potentially dangerous nature. Messing around with the inside of your monitor can hurt you, it can potentially kill you. This is not a joke. Trying to save a few hundred dollars at the expense of your health or life is a poor trade. If you don't know what you're doing, don't do it.

-------------- HeadRusch's message follows --------------

I realize that monitors, TV's, etc are all basically "one big death sandwich if you bite the wrong place!"....but these flimsy plastic cases protect us!

The scary part comes when you take the plastic casing off.  Rather than take the case off my 20" TV, I taped the glass and painted it that way..which worked fine.

But the fact remains that my cab would take a 25" TV or 25" Arcade monitor if only I didn't have to deal with an inch or two of plastic on either side.  So my question is this.......are the only real dangerous areas on a monitor on its ass-end?  I realize this is a "stop being a ---Bad words, bad words, whatcha gonna do? Whatcha gonna do when saint censors you?---" kinda situation, but I do fear for my safety when thinking about taking the case off a 25" TV or buying a 25" Arcade monitor and plopping it in my cabinet.  I fear I'll be reaching around to adjust convergence or something or trying to adjust the magnets on the gun (if I had to) and ZZZZZZAAP.

IS one way around this simply to wear rubber gloves when doing work on a monitor?  Or are arcade monitors 9without plastic cases) simply as safe as any TV or PC monitor that has its case OFF.

[paigeoliver]

I used to be scared to death of monitors and TVs too. Until I got used to them.

Just learn how to discharge the tube and all your worries will go away. Even discharging stops being scary after the second time.

Basically just be careful making adjustments. Don't pull the suction cup off the tube. And don't do ANYTHING to a TV when it is on (HOT chassis).

If your monitor has a broken neckboard that has been repaired you should avoid adjusting anything on the neckboard while it is on. Otherwise just be careful. It wouldn't hurt to get a plastic screwdriver to make your adjustments with.

Also. Don't reach around in back blindly. Instead prop up a mirror so you can see the picture from behind.

Most of your crucial adjustment knobs are right at the back of the board anyway. There may also be a couple on the board slightly inside. Those very rarely have anything dangerous in the direct vicinity.

[HeadRusch]

I just picked up a coctail cabinet last night, and am going back on Sunday to help my buddy wrestle an old Berzerk cab into his truck for his own MAME project.  

When I'm up there, I think I might ask the guy to show me how he discharges a monitor.....he's got dozens upon dozens of them all over the place...I told my buddy "yous ee these monitors, seriously, don't touch them..anywhere" as we were browsing the stuff he had available.  Wactched a nice Pole Position cab (stripped) make its way into a minivan on the road to restoration.

Anyhow, I understand that the suction cup is where all the magic happens, its the rest of the board and the frame that have me worried.  Granted, this is becuase I "just dont know" and I might not have anything to be worried about, but the same applies to PC monitors and TV's......is it ok to hold em by the frame? Is it ok to hold the frame and the glass and the metal surrounding the glass screen up front when positioning...etc...etc.

You're right though, once you learn how to discharge one, they become much more managable.

[rampy]

I just picked up a coctail cabinet last night, and am going back on Sunday to help my buddy wrestle an old Berzerk cab into his truck for his own MAME project.  

When I'm up there, I think I might ask the guy to show me how he discharges a monitor.....he's got dozens upon dozens of them all over the place...I told my buddy "yous ee these monitors, seriously, don't touch them..anywhere" as we were browsing the stuff he had available.  Wactched a nice Pole Position cab (stripped) make its way into a minivan on the road to restoration.

Anyhow, I understand that the suction cup is where all the magic happens, its the rest of the board and the frame that have me worried.  Granted, this is becuase I "just dont know" and I might not have anything to be worried about, but the same applies to PC monitors and TV's......is it ok to hold em by the frame? Is it ok to hold the frame and the glass and the metal surrounding the glass screen up front when positioning...etc...etc.

You're right though, once you learn how to discharge one, they become much more managable.

*cough* headrusch... where's this haven of MAME-able cabinets you speak of (assuming driving distance from CT, right?) is it in Enfield or someplace else?

PM me if you wish or drop me an email...

gracias,

rampy

[paigeoliver]

Anyhow, I understand that the suction cup is where all the magic happens, its the rest of the board and the frame that have me worried.  Granted, this is becuase I "just dont know" and I might not have anything to be worried about, but the same applies to PC monitors and TV's......is it ok to hold em by the frame? Is it ok to hold the frame and the glass and the metal surrounding the glass screen up front when positioning...etc...etc.

You're right though, once you learn how to discharge one, they become much more managable.

Ok. Arcade monitors. The frame is perfectly safe while the monitor is on or off, as is MOST of the PCB (you really have little chance of shocking yourself on the PCB unless you start touching stuff on the underside while it is on, and you can't do that anyway because the frame is in the way. Only thing to really be worried about is the neckboard PCB, as it can accidently be knocked off, which can cause a bit of a spark and light show.

TVs. Don't touch anything while they are on. When they are off, then you can touch the tube or mounting holes, or pretty much anything else you can touch on an arcade monitor. If you decase a TV monitor I suggest installing it where you CAN'T manage to touch anything on it without major effort.

OR.

You can bolt a TV tube/chassis into an arcade frame and add an isolation transformer, at which point it starts following the arcade monitor safety rules instead of the TV rules. Do not bolt a TV into an arcade frame without adding an isolation transformer, as that will result in a frame that has house current running through it (UNLESS you install the tube with no metal to metal connection between the tube mount points and the frame, like if you used plastic spacers, and NOTHING else metal is touching the frame). Also, please research the whole "TV in an arcade frame" thing before you even think about it. I am repeating something else I read from memory here, and I may have gotten something wrong.

Matter of fact, if you have a good TV and an arcade frame, you might as well buy one of the special CHASSIS from 8liners.com that just turns it into an arcade monitor. The image quality will be much better anyway. (You can also do this to TVs without putting them in arcade frames, so you could get a cheapo 27" TV, and 8-liners arcade chassis for it, and an ARCADEVGA and get great image quality cheaper than what an actual new 27" arcade monitor would cost, and it would still be in the plastic case when you were done, so no need to be scared of anything).

[HeadRusch]

Hmmm.....well it sure is tempting to go arcade-monitor route..but since my TV doesn't have 10 hours on it yet, I'll deal with it for now...when the time comes to change, I'll definately consider an arcade monitor...and being a smarter mammal rearding safety around it.

Thanks for the great explanation, btw.

[paigeoliver]

Hmmm.....well it sure is tempting to go arcade-monitor route..but since my TV doesn't have 10 hours on it yet, I'll deal with it for now...when the time comes to change, I'll definately consider an arcade monitor...and being a smarter mammal rearding safety around it.

Thanks for the great explanation, btw.

8liners.com chassis turns your TV into an arcade monitor, which is worthwhile for a big tube, but a waste of money for a small one (why pay $100 to retrofit a 19" TV when you can get a usable 19" arcade monitor for $50 or $60, a good one for $70-$80, and a nice recapped/rebuilt one for $100 and a new one for $200).

[MameFan]

A few comments. No intent at all to Diss PaigeOliver, just wanted to add more useful information.

> why pay $100 to retrofit a 19" TV when you can get a usable 19" arcade monitor for $50 or $60, a good one for $70-$80, and a nice recapped/rebuilt one for $100 and a new one for $200

Well, if you have in your house or find at thrift stores/rummage sales/garbage bins, you can find old 1980's 19" sets with virtually no burn in for as little as free to at most $20 at most places.. So your total cost is <$100 with new chassis and old tube.  A recapped arcade monitor still may have a burned in or dulling tube and may need a tube swap eventually too. But I agree... new chassis is not for everyone, but if you're going to pull off an 25 year old chassis to put in a cap kit (a couple hours work, plus parts)...perhaps its just easier to get a new chassis outright that may not have other issues beyond needing a cap kit.


>(you really have little chance of shocking yourself on the PCB unless you start touching stuff on the underside while it is on...

Actually I wouldn't say that..  If you touch anything on the high voltage in or out side (like high voltage transistor, fuse clips, leads on resistor, resistors next to the flyback) you can definitely kill yourself.   I NEVER touch anything in a monitor when it's on directly.. I always use a nylon/plastic insulated tool to do any adjustments of pots/coils or to poke/prod.  You can never be sure what is sticking out.. And if you accidentially feel a small voltage, you will naturally (consiously or not) pull your hand away.. RIGHT into the sharp metal edge of the frame or right into the fragile neck of the tube.... thus secondary damage/harm to yourself.


> If you decase a TV monitor I suggest installing it where you CAN'T manage to touch anything on it without major effort.

(I know you touched on this in the next paragraph, but....) I'll extend that to say "If you decase a TV, you MUST install an isolation transformer on the power line because SOMEONE will eventually think it's just a normal monitor and go touch something grounded (or stupidly run a ground wire in the cab from the coin door or something to it) and POOF massive shock followed by numerous things blowing out ruined by the grounding.   If you isolate it, then it's the same level of "safety" as an arcade one.  An isolation transformer is like $12... WELL worth the investment.


> Don't pull the suction cup off the tube. And don't do ANYTHING to a TV when it is on (HOT chassis).

Technically it isn't a suction cup, just an isolation measure to keep electrons from jumping from the aquadag on the outside of the tube to the ones exposed just under the center of the anode cap that contacts electrically with the inside of the tube.


Basically, if you've never worked with CRTs (arcade monitors, TV's) you SHOULD be scared to death to work on them... That's better than thinking you can easily do whatever you want, because then you won't be scared to death, you'll just be shocked to death

However as Paigeoliver said... once you gain knowledge (by doing, an d not just reading), then it becomes increasingly easier and you can more easily do things.