baeuchlein on 3/4/2006 at 12:30

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I have seen two monitors which had some hardware to give a computer program access to the monitors internal controls, but I have not yet seen any monitor which does not have at least a few basic controls inside, and bikerdude almost certainly meant one of them.



What you need to find is not the coil itself, but a kind of knob you can turn. The knob controls a voltage in the monitor which regulates the brightness of the monitor. This knob covers a much wider range of brightness than any of the controls you find outside of the monitor.

However, the danger of receiving a harmful electric shock is present in this case, as the knob is usually located near an electronic circuit in the monitor where the strongest electric current present in the monitor goes through. And there are usually some capacitors around this circuit which might even keep some electric charge for some time if the monitor is turned off. These capacitors are usually cylindrical objects standing upright on the "bottom" of the monitor's electronics.

A wise rule here is not to touch anything in the monitor, especially since you can only adjust the brightness properly with the monitor turned on. But there's an easy way to do this.

The knob you need to turn is shaped like the head of a screw. You're supposed to turn the knob not with your finges, but with a screwdriver. Usually, this is a Philips head screwdriver (with a cross-shaped blade), but one can use another screwdriver as well. A screwdriver made of plastic would be ideal. Rumours say such screwdrivers exist, but I have not seen one yet. Second on the hitparade are screwdrivers which are plastic-coated, and those are quite frequent. If you own one that fits the knob's head, use it.

If you don't have one of those, use a screwdriver with a plastic or rubber ending at the end where you grab the screwdriver. This way, you're still not electrically connected to your monitor if you accidentally touch a wire in there.

Finding the knob is not as difficult as it seems. It is usually located on the side of a large black block sitting on the bottom of the monitor. You will find two or sometimes three knobs there, and they're usually labeled "Focus" and "Screen". "Screen" is the one you're looking for. If you can't see much inside the monitor, try to use a flashlight.

To change your (CRT) monitor's brightness, you should do the following:

1. Turn off your monitor and unplug it.

2. Find out how you can open it's cover. This is usually done by removing four or five screws accessible from the rear (or sometimes from below) of the monitor.If this does not work, ask around in forums; there are some unusual ways of opening a monitor's case, but one does not find them too often.

3. Remove the cover, but try to touch only the cover itself, and nothing inside the monitor. Usually, there are no dangerous parts near the edges, but better be safe than sorry.

If the cover does not come off, you should try to lift it off upwards and to the rear - several covers will only come off if pulled away from the monitor at an angle.

4. Search near the bottom of the monitor for the afore-mentioned black block with two or three knobs on one side, possibly labeled "Screen" and "Focus".

5. While the monitor is still not turned on, practice inserting a screwdriver into the knob. Do not turn it yet!

6. Once you're sure you can insert the screwdriver without hitting anything else in the monitor, reconnect the monitor to the power outlet. Turn it on, turn on your computer and wait about 10-15 minutes for the monitor electronics to warm up.

7. Start "Thief" and ensure you are in a comparatively dark place in the game. In "Thief", a place near the end of the sewers accessible by the well should do fine: It's quite dark near the entrance to Bafford's cellar. In "Thief II", just start the first mission and walk away from the courtyard. You should stand in the dark pretty soon. Now you have a picture on your screen which is dark enough.

8. Ensure that the light in the room is at a level which you usually have when playing "Thief". If you prefer to play in the dark, wait until it's dark. (If you can't see the knob inside the monitor then, use something like a flashlight to lighten up the area around the knob.) If you play only during the day, wait until the sun is up, or turn on enough lights in the room.

9. Adjust brightness and contrast on the outside of the monitor. Try to set both to medium levels, regardless of how the picture looks.

10. Insert the screwdriver into the knob inside the monitor and carefully turn it. Those controls are much more sensitive than the ones outside of the monitor.

If your picture gets blurred, you're turning the Focus knob instead of the Screen knob. Turn it back carefully until your picture is OK again, then insert the screwdriver into the other knob and try again.

If the picture's brightness changes, you have found the right knob. Turn it slowly until brightness is okay.

11. If necessary, adjust the picture some more with brightness and contrast controls outside the monitor.

12. Turn off the monitor, pull out the power cord, then put the cover back on. After that, you can reconnect the monitor to the computer and the power outlet.

Done.

If you're still not sure whether you should poke around inside the monitor, you might ask a friend who knows a bit about electrics and electronics. Maybe he/she can do it for you. I have watched a friend of mine doing monitor surgery first before trying it myself.

There are three main dangers when working inside a monitor, and all can be avoided easily.

a) Touching a part which sends high electric currents through your body can be disastrous to your health. Solution: Use screwdrivers and other tools to access a monitor's internal controls without touching anything.

b) Touching some sharp part inside might cause pain, and if your reflexes let you pull your hand away from the part, you might hit other parts inside. Solution: Same as for a), just keep your hands out of the monitor and use tools to access anything.

c) Breaking the glass tube present in the monitor will cause it to implode, which will have effects similar to an exploding glass tube. Splinters will fly away from the inside at high velocities (they may fly 30 meters or more until they hit the ground again), and usually your face is in the way. Solution: Don't hit the glass tube forcefully, and don't lift heavy tools across the tube (they could slip from your hands and fall down); rather move them around the monitor.

The tube is usually protected somewhat against such events, but it's still just some kind of glass. The tube is most vulnerable near it's neck - don't break it off.

It is dangerous to work inside a monitor, but if you know what you're doing, it's not so difficult to avoid these dangers - it's just like driving a car.

Luthien on 4/4/2006 at 07:03

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1b. Wait at least six hours before touching anything inside the monitor - unless you want to risk receiving a lethal electrical shock.


It doesn't protect you at all if you touch anything with your hands.


See above.


Do not do that!. You risk being *killed*. Never ever insert anything into a monitor that is plugged in (or has been plugged in in the last couple of hours).

Either take your time allowing the device to discharge or ask an electrician for help.

Aja on 4/4/2006 at 21:59

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Heh, no, I haven't done anything yet.

I have read elsewhere that it's best to wait MONTHS for the capacitors to drain before attempting anything... six hours is it??

And obviously I wasn't going to touch anything with my hands. Is there any way to ground yourself?

baeuchlein on 6/4/2006 at 13:23

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This is one of the best ways to discharge the capacitors. Modern monitors should even discharge their capacitors themselves within two or five minutes after disconnecting power, but neither does anyone guarantee that the monitors do this, nor will all older monitors do this. A few of them need months to discharge the capacitors because their electric circuits were not designed to do this. Usually, however, a few hours are long enough, so take Luthien's advice (1b. on the list), and this should not be a grave danger anymore.

A safe way to discharge the capacitors would be to lead their electricity into something which uses it, thereby removing the electric charge. Unfortunately, this is hardly possible for anyone who does not have the blueprints for this specific monitor. If you do not have the blueprints, you would have to connect something to the capacitor's soldering points on the monitor's electric board, but those are usually located below the board. This means you would have to disassemble large parts of the monitor, which would not be a good idea as long as these capacitors are charged. However, unless you did it nevertheless, the capacitors could stay charged... this situation cannot be reasonably resolved.

One should let the monitor try to drain the capacitors, and just for safety reasons pretend they're still charged.





Exactly. The plastic handle will only protect you if you accidentally touch something inside the monitor with the screwdriver's blade, and only if you keep your hands off this blade. If one touches the blade which is connected to something else, one might get shocked if this "something else" is charged or powered up - and only if there is a reason for the electric current to run through one's body. Which brings us to the following:



Yes, there is - but it could actually be harmful in this case. If you ground yourself, an electric charge might run through your body instead of staying in the monitor.

If a bird sits on an overland high voltage line, it's not harmed. The electric current running through the line cannot go through the bird's body, because nothing closes the electric circuit - the air works as an insulator here. If, however, you ground the bird, it'll be immediately roasted because a significant part of the electric current would run through the bird.

You may ground yourself before doing things in the monitor, but then you should consider removing the grounding bracelet (or whatever connection to ground you have established). The main problem here is not to get yourself damaged or killed when working inside the monitor. To protect the electric components against being shocked by an electric charge in your body is a lesser goal: You can always buy yourself a new monitor if you shock it, but you can't buy a new version of yourself if you get shocked to death.

And as Soul Shaker said, you can coat yourself in rubber, or at least wear rubber shoes and such. I usually sit on a wooden chair if possible, and lift the feet (placed in shoes with rubber soles) off the ground. When I was connected to a power outlet on the wall by accident several years ago, I almost noticed nothing due to some shoes with thin rubber soles. Rubber does protect. Plastic can do the same, that's why I recommend plastic coated screwdrivers like the ones Soul Shaker mentioned.




Usually, this would be absolutely correct, but in this case it is not possible. If you switch off the monitor, how could you adjust brightness?

If one is still unsure about working inside a monitor, he/she might check out the Sci.Electronics.Repair FAQ ((www.repairfaq.org)). The section about TV sets and computer monitors is here: (http://www.repairfaq.org/sam/monfaq.htm)

The chapter "Focus adjustment" deals with almost everything I discussed here, but it centers around the other knob near the "Screen" knob. But as one can imagine, safety precautions and other things remain the same, only the exact function of the knob is different.

You can not avoid the dangers present here completely, but you can take some precautions and lower the danger to your health sufficiently. If you board a plane, you might die from a plane crash, but many people do it (boarding, not dying). And a majority of them even survives multiple flights. It's dangerous, but not necessarily deadly.

If, however, a qualified electrician or someone similar is available, talking to him/her won't hurt too much - although many of them might not appreciate people poking their heads into their holy machinery. One of those really got angry at me some years ago when we had a VCR without sound and I admitted I had tried to repair it. Of course, he gave it up, then.

Guess who successfully repaired the VCR in the end...

Aja on 8/4/2006 at 18:55

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BREAKING NEWS

Took apart this monitor this morning, sure enough there was a small black box with three (plastic) knobs - one for horizontal focus, one for vertical focus, and one marked "screen". It was a sensitive little bugger but I managed to adjust it so the blacks are pitch. It looks wonderful now.

Thanks guys, you saved me a trip to the repair shop!