Space Invaders Deluxe monitor

AAirhart

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Anyone with any experience with the black and white monitor in a SID?

My monitor is pretty dim and in need of a cap kit and the flyback is whining.

Any suggestions on working on this one (anything going to blow if i discharge it as I've read with some black and white monitors)?
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Personally i would get a new fly back and a cap kit before before i worry about adjusting the brightness..

Brightness can be as simple as adjust a pot on a remote board or a pot on the video board or adjustment on the fly back itself..

I don't recommend adjusting a flyback if it's making hissing noises unless you like to get shocked...
 
well look at it this way better safe than sorry. try and find some one locally with a high voltage probe and bleed it off slowly.

i would do that rather than possibly have to buy more parts.

i really like my HV probe i use it all the time to fix monitors.

Peace
Buffett
 
Those black & white monitors have a high voltage diode inline with the anode cup. I've seen many times where the diode isn't making the best connection, and can hiss/whine/etc.

Turn off your room lights and fire up the machine....if it's leaking anywhere, maybe you'll be able to see the "spark".

Regarding discharging......the tube bleeds off in about 30 seconds....at least on the Wells-Gardner V1000 models and the Motorola "M" series.

Edward
 
Personally i would get a new fly back and a cap kit before before i worry about adjusting the brightness..

Brightness can be as simple as adjust a pot on a remote board or a pot on the video board or adjustment on the fly back itself..

I don't recommend adjusting a flyback if it's making hissing noises unless you like to get shocked...

Uh... Have you ever worked on a black and white monitor? They don't have the integrated screen control in the flyback. Furthermore, new flybacks are not available.

Black and white monitors do generally have separate brightness and contrast controls

But, anything is all speculation at this point, as we don't even know what monitor he's got in there.

One thing that does ring true with black and white monitors is that when discharging them, you should use a bleeder resistor so you don't blow the HV diode. I just soldered 10 1k resistors end to end and encased them in a BIC pen barrel and added alligator clips.

-Ian
 
Uh... Have you ever worked on a black and white monitor? They don't have the integrated screen control in the flyback. Furthermore, new flybacks are not available.

Black and white monitors do generally have separate brightness and contrast controls

But, anything is all speculation at this point, as we don't even know what monitor he's got in there.

One thing that does ring true with black and white monitors is that when discharging them, you should use a bleeder resistor so you don't blow the HV diode. I just soldered 10 1k resistors end to end and encased them in a BIC pen barrel and added alligator clips.

-Ian

Have I worked on black and white monitors? Simple answer. Yes, I keep forgetting that arcade monitor were always built to be cheap. A different design from the Industrial black and whites of my day when dropping 2 to 4 grand on a 19" was common. Maybe medical monitors I worked on hard the had the brightness control on the flyback. I slightly recall the a conversation about how crazy it was to have adjustment on a flyback in the first place.

Yes, I agree is all speculation on where the brightness controls are.
But as I said "Brightness can be as simple as adjust a pot on a remote board or a pot on the video board or adjustment on the fly back itself." I have dealt with black and whites which had adjustments in these location.

10 to 15 years ago, It was possible to find any flyback just by calling your local electronics rep. The collapse of the electronics manufacturing sector has just made parts hard to impossible to find.

If you can not find a new one as Ian has suggested, Your might have to find another board or another user who has a chassis that will work on your monitor. Or maybe a monitor to replace.
 
If you can not find a new one as Ian has suggested, Your might have to find another board or another user who has a chassis that will work on your monitor. Or maybe a monitor to replace.

Or, we could always do a tiny bit of troubleshooting to see what his problem really is...

All we have to go on is that it's dim and he hears a whining sound. Is it the flyback? Who knows? He doesn't even know what kind of monitor it is, so he hasn't looked at it yet.

The dim picture could be a weak tube, a misadjusted brightness control, or the face of the tube could just be really dirty (common on Space Invaders, since the tube faces up, with a mirror to reflect the image).

The whining noise can be any number of things - from a loose flyback core to a bad transformer, loose yoke winding, loose width coil, or the hold being slightly out of adjustment. It's also pretty normal for a flyback to make a bit of a buzz if the center core is loose, in which case you can shim it up with a toothpick. Might even be one of the flourescent light fixtures in the game, and not the monitor at all!

It's just that as soon as someone posts a problem everyone jumps all over it listing tons of parts to replace, without actually doing any diagnosis, or even knowing what the device in question is! Sure, all monitors this old probably need to be capped, since electrolytics fail with age. But you have to start with troubleshooting. Clean it up, check it out, check the voltages, see what is _actually_ wrong with it, before changing out tons of components.

-Ian
 
Or, we could always do a tiny bit of troubleshooting to see what his problem really is...

All we have to go on is that it's dim and he hears a whining sound. Is it the flyback? Who knows? He doesn't even know what kind of monitor it is, so he hasn't looked at it yet.

The dim picture could be a weak tube, a misadjusted brightness control, or the face of the tube could just be really dirty (common on Space Invaders, since the tube faces up, with a mirror to reflect the image).

The whining noise can be any number of things - from a loose flyback core to a bad transformer, loose yoke winding, loose width coil, or the hold being slightly out of adjustment. It's also pretty normal for a flyback to make a bit of a buzz if the center core is loose, in which case you can shim it up with a toothpick. Might even be one of the flourescent light fixtures in the game, and not the monitor at all!

It's just that as soon as someone posts a problem everyone jumps all over it listing tons of parts to replace, without actually doing any diagnosis, or even knowing what the device in question is! Sure, all monitors this old probably need to be capped, since electrolytics fail with age. But you have to start with troubleshooting. Clean it up, check it out, check the voltages, see what is _actually_ wrong with it, before changing out tons of components.

-Ian

Yes Ian I do agree with you that we should diagnosis what the problem. It's not easy to give the right answer to the person who asking for help with so many unknowns. If you were working on this monitor on your bench in front of you or many others here. I am sure we could fix it in a short time.

We have given our best guess advice with sketchy input. We know that there are caps that fail with age and need to be replaced. While most of use are handy with a soldering iron and have lots of test equipment and experience to use them. Sometime we forget others do not have these same skill sets. Sometime even if it's just a tooth pick repair ( I uses bamboo sticks my self ). A complete board replacement or sending it out to get repaired might be the easiest way for this person to handle the problem of course depending on his skill level.

Just on the bases of what AAirhart said that there was a noisy flyback. I suggest replacement. If the core was loose, This would have fixed it. Since there was nothing mentioned about the picture not being stable. I didn't think it was a loose width coil nor a loose yoke winding.

It's been my practice that if your going to replace a flyback, You might as well replace do a cap kit. While it may not have needed it. It just extends the working life of a monitor. I think spending less than 20 bucks to extend the life of a monitor is cheap insurance.

While you make a good point that checking the voltage is a good first step. Since the only problem reported was a Dim screen and a noisy fly back. I figure the voltages where ok or maybe a bit low replacing the caps would change the voltages readings. Adjusting them before replacing the caps Just means you might need to adjust them after the cap kit was installed.
 
The picture is stable with a little bleeding like a monitor in need of a few new caps, almost looks slightly out of focus. See the picture at the beginning of the thread. A few of the caps look like they have leaked a bit and are bulging at the top, so those are going to need swapped.

Brightness adjustment pot works, but doesn't improve the issue, just turns the screen a dull white. Contrast pot seems a little out of wack, so that's getting cleaned. I don't see anything for brightness near or on the flyback. I'll get the model # in a few mins.

No whining coming from the light fixture, it's coming from right around the flyback. Hard to pinpoint with it in the cab still, but not the light (removed all power from it and the whine remains, can hear it from right inside the coin door to the left) The starter and bulb were also replaced (using a white black light)

The front of the tube has been cleaned, along with the overlay and the mirror, so no dirt there.
 
Model - WG V1001

After cleaning the contrast pot the focus issue is resolved, just needs to be just a little bit brighter.

I do sort of agree with the approach of just recapping after a flyback (I do the HOT if cheap and available). I'm better with g07s though than pretty much any other monitor.

The whining is not coming from the flyback but what sort of resembles an isolation transformer...which is slightly off to the left of this pic.
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The beast from the outside
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One thing that does ring true with black and white monitors is that when discharging them, you should use a bleeder resistor so you don't blow the HV diode. I just soldered 10 1k resistors end to end and encased them in a BIC pen barrel and added alligator clips.

WHOA WHOA WHOA. 100kOhm at only 5kV is a whopping 250 Watts. And aren't we talking about a 19" tube? If you use the 1"=1kV rule, that's 19kV, or almost 4000 watts! Resistors small enough to fit in a BIC pen barrel won't take 1W, leave alone 4000/10=400. When you find a monitor that actually needs the discharge, your little contraption is gonna explode.
 
WHOA WHOA WHOA. 100kOhm at only 5kV is a whopping 250 Watts. And aren't we talking about a 19" tube? If you use the 1"=1kV rule, that's 19kV, or almost 4000 watts! Resistors small enough to fit in a BIC pen barrel won't take 1W, leave alone 4000/10=400. When you find a monitor that actually needs the discharge, your little contraption is gonna explode.

OK, one, I made a typo - I used 100k resistors. Two, the power and current here are negligible, it's a stored charge with nothing behind it. I assume it could, in theory, explode if for some reason you tried to discharge it while it was running... I've used several different types of resistors for this over the years - 100k most definitely does not explode. The only reason to use a resistor at all is to reduce the strain on the HV diode.

Either way, by your logic, discharging a monitor without the resistor, just a cliplead and a screwdriver (assuming a resistance of 1 ohm), means you're putting 361000000 watts through the cliplead.

Please to be commenting about things you have experience with.

-Ian
 
OK, one, I made a typo - I used 100k resistors.

Okay, that's understandable. I apologize for overreacting. By the equation, that's about 400W or so at the outset -- for such a short spark they'd probably be fine.

Two, the power and current here are negligible, it's a stored charge with nothing behind it. I assume it could, in theory, explode if for some reason you tried to discharge it while it was running... I've used several different types of resistors for this over the years - 100k most definitely does not explode. The only reason to use a resistor at all is to reduce the strain on the HV diode.

Okay, enlighten me. Is the capacitance of the tube too little to actually deliver the current of a dead short, even for an instant? Then how does it sustain such a voltage? Or is the static charge limited to a fraction of the operating voltage by precisely that mechanism?

Either way, by your logic, discharging a monitor without the resistor, just a cliplead and a screwdriver (assuming a resistance of 1 ohm), means you're putting 361000000 watts through the cliplead.

My understanding is, one, it's less than 1ohm, likely far less, and two, the charge is spread out across a much larger conductor than the tiny element in a resistor, distributing the heat produced. Wire-wound resistors (as opposed to, say, silicon) can likely handle momentary spikes of far more current than they're rated for, but at some point, vaporization sets in, no?

Back to the topic at hand -- are those factory caps!? They certainly look dusty enough. I'd start with a capkit.
 
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