Tatung VS-14428 monitor issue ... horiz lines at top

[shortrackskater]

I recently bought another Game Maker. It's an earlier model with a 13" Tatung monitor. My camera "removed" the discoloration on the white cards but it's clearly visible to the naked eye, that the white is very yellowish. The other issue is there's tearing and horizontal lines at the top of the CRT. None of the adjustments do much. Also, for the best picture, in its current condition, you have to have the brightness and contrast all the way up.
I'm not as knowledgeable on monitors but I guess it's time for me to learn some more.

[rickhunter]

You probably need to recap it for the weird sync issues. As far as the color, that is another story. 

[shortrackskater]

I read an old post where there was "too much blue" and the reply was to warm up the tube, then lay it on its face and tap the neck with a screwdriver...
UPDATE:
I pulled the monitor, and made sure the RBG controls were marked. Then I just sprayed the pots and turned them a few times. My white is back. The colors are fine now.

Still - I wonder how hard it is to locate a replacement monitor? I've never recapped although I do have good soldering skills. The monitor is a Tatung VS-14428.

[shortrackskater]

 

[shortrackskater]

Does anyone know a place or person who would either fix this one or trade mine and $$$ for a working one?
 
Is there anyone here anymore?
A year ago, I'd have 4 replies... what the heck has happened to NLG?   

[rokgpsman]

Is there anyone here anymore?
A year ago, I'd have 4 replies... what the heck has happened to NLG?   

Wednesday nite, everyone is

1) at church   
    or
2) bowling & drinking !@!???   

[rokgpsman]

I recently bought another Game Maker. It's an earlier model with a 13" Tatung monitor. My camera "removed" the discoloration on the white cards but it's clearly visible to the naked eye, that the white is very yellowish. The other issue is there's tearing and horizontal lines at the top of the CRT. None of the adjustments do much. Also, for the best picture, in its current condition, you have to have the brightness and contrast all the way up.
I'm not as knowledgeable on monitors but I guess it's time for me to learn some more.

on the brightness issue,

If that is a crt monitor then after several years of no telling how many thousands of hours the cathode on the gun just starts running out of electrons to emit or it gets a coating that blocks emission. Either way your stream of 'trons gets weaker. And that reduces brightness. Sometimes on the monitor circuit board running things there is another master adjustment for brightness limiting (it is set at the factory to limit how much the operator can crank up the brightness) and you can increase it a little to make your front brightness adjust not be at the end of its range. Sometimes you can also up the high voltage adj a little so the electron beam is attracted more strongly to the front of the screen. But all of this is a bandaid for a crt that's just got a lot of miles on it. Also, there is a phosphor coating on the inside of the screen that glows when the electrons bombard it. The phosphor gets weaker as the decades go by.

Be careful, if you crank things too far you can get blooming or other problems. AND be careful noodling around in there, even with power off the crt holds a large charge enough to shake your pickle.

Actually the brightness on it looks pretty good to me. It doesn't hurt if the brightness pot is at the end of its range as long as you are happy with the brightness level. I'd concentrate on the tearing at the top of the screen. I agree with rick that cap replacement takes care of a lot of problems on older crt monitors. There are place that do cap jobs, maybe one in your town. Check with any tv repair shops that are still around, computer monitor repair places or even arcade places to see if they know anyone that does that kind of work.

[CVslots]

AND be careful noodling around in there, even with power off the crt holds a large charge enough to shake your pickle.

Oh my, "shake your pickle"...that has to be the best saying EVER...

Thank you rokgpsman! You have made my night!

[rokgpsman]

AND be careful noodling around in there, even with power off the crt holds a large charge enough to shake your pickle.

Oh my, "shake your pickle"...that has to be the best saying EVER...

Thank you rokgpsman! You have made my night!

you're welcome Roz,
glad to see you got back from church tonight all safe & sound,
feel free to shake a pickle of your own...
[and that could really make your night].....(don't want to offend any of the genteel users)

[shortrackskater]

Mine too!
I'll try the brightness master and see if it makes a difference. It seems just a tad low.
I did try a couple TV repair places near my home. One didn't answer, one said he didn't work on Tatungs! 
If it's not too expensive, maybe I will buy a cap kit provided I can find a source. It might be fun!
 

[rokgpsman]

If it's not too expensive, maybe I will buy a cap kit provided I can find a source. It might be fun! 

this might be close to what you need:
http://www.ebay.com/itm/Tatung-VS-14428-VT-1440S-Cap-Kit-Get-Well-Kit-for-Monitor-Repair-/200889563465

and more info is attached, hopefully for your particular VS-14428 monitor:

[shortrackskater]

Your one step ahead of me! I just saw that on ebay and was about to post!
Thanks!

Although... looking at my monitor... I don't want to damage my pickle! I've never taken out a circuit board out of a CRT.

[rokgpsman]

To remove the monitor main board you have to disconnect it from a few things associated with the crt. If you don't feel like doing this then you shouldn't. Look it over and figure out the least things you have to disconnect. There is often a small board or assembly on the narrow end of the crt, it has some cables that go to the larger main circuit board. Remember, just because it is turned off and unplugged there is usually voltage still stored in there ready to bite you.

There is usually a cable that is taped or wrapped somewhere around the entire backside of the big end of the crt. This cable should have a connector for plugging into the main circuit board. This is the degaussing coil that demagnetizes the crt each time the monitor is turned on, it helps with the purity of the screen image.

The scary part is the crt hi voltage cable. While the monitor is operating it is roughly 1,000 volts per inch of size on the screen, so figure on 13,000 volts or a little more. When the monitor is turned off this voltage is still stored inside the crt itself, it acts as sort of a capacitor for all of that electrostatic charge that was on it. There is a heavy round wire, a lot of times it is red, that connects to the side of the crt glass. This is the high voltage lead to the crt. There will be a round rubber suction looking piece at the end of the crt hi voltage cable. There is a metal clip under that round insulator, it fits into a hole in the glass on the side of the crt, usually on the top side somewhere. Removing it is where you have to be the most careful because that clip attaches to the high voltage lurking inside the crt. Although the electrical current capability is relatively not that much the voltage is so high it is still dangerous. Some guys use rubber gloves and insulated tools like needle nose pliers to remove this hi voltage lead. You don't want to use anything conductive like a screwdriver blade. Hopefully you just pinch and twist on the rubber cap and the connection comes loose. There are ways to discharge the tube and get rid of the high voltage, this is especially needed when the crt is getting replaced, don't want a dangerous old crt sitting around to hurt someone. You can google "discharging crt" to see how it is done but it probably isn't needed since you just want to remove the main circuit board and replace the caps. Depending on the room it might even be possible to replace some of the caps without even removing the circuit board.

Below are some generic pictures to give you an idea, your monitor will be similar but not exactly the same.


BEFORE you do this I think you need to think about it carefully and maybe get some opinions and tips from others here. This is a for-real, no-sh*t-sherlock kind of deal that can ruin your day if it goes wrong. It isn't like dinking around with other mechanical parts of the machine and seeing how it goes. You have to be careful and only have to make 1 mistake to get your teeth chattering.

[shortrackskater]

While you were writing this probably, I was watching a few videos on discharging the voltage from the CRT, and also how that anode connector comes off.
It doesn't look so bad now... I think I can do this!
I'll look close at the pictures and probably do some more reading. I'm also not sure which caps go where but since that kit is specific to the monitor, I'd assume I can just find them all and then replace them one at at time.

[rokgpsman]

Usually the circuit board will have writing on the board next to the capacitor saying something like "C9". So hopefully the kit will have a paper listing the capacitor designations (names) of all the caps that get replaced. Also, the value of the cap is written on the side of the cap, you should check it with the one you will be replacing it with as a double-check to make sure they match and that you are using the right part at the right place. Also, many caps are polarized, meaning they have a plus and a minus (positive & negative) side. Important to get the plus lead in the plus hole.

attached is a bare board that shows how they write the component designation name on the board itself and another picture of a board with parts soldered in.

also attached are photos of polarized capacitors. Notice the first one has negative signs (minus signs) written along one side that align with the shorter lead. The second cap has a + mark by the positive lead. On polarized caps there will be a marking that shows the negative or the positive lead. Keep in mind that there are capacitors that are not polarized, you can install them in either direction, so they won't have polarity markings.

When doing a monitor recapping job most (or all) of the caps will be polarized, as these are the usual type of filter caps that dry out over the years and go bad. There is a moist chemical paste inside some capacitors and that chem is what dries out. As the cap goes bad it can develop internal resistance and run hotter, this can dry out the cap and it stops working. Or if there is enough heat it can cause the moist chem to evaporate quicker and create gas pressure inside the cap body. That sometimes causes pressure to build up too much inside the sealed cap and the flat end will start to bulge and can eventually rupture. A rounded or bulging flat end to a cap can indicate it is failing.

[shortrackskater]

Thanks for the pictures! This definitely helps. Cap kit is on the way. I'm doing this. 

[rokgpsman]

Thanks for the pictures! This definitely helps. Cap kit is on the way. I'm doing this. 

Good luck with it and let us know how it turns out.

channelmaniac here on NLG may be able to help with specific questions if you run into problems.

[rokgpsman]

Thanks for the pictures! This definitely helps. Cap kit is on the way. I'm doing this. 

Bally crt monitor discharge procedure:

[cowboygames]

A clip lead from the shank of the screwdriver to the grounding strap on the tube helps a lot.
But then again, so does a high voltage probe...

[rokgpsman]

Yep, all true.

The guy I worked with used to say "First you set your coffee cup down"....