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#1
06-14-2013, 12:31 AM
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Horizontal issues
I know this isn't exactly a television but I'm kinda desperate here.
I have a IBM 5154 EGA monitor and according to the previous owner it has been like this since the mid 90s. I got th monitor for free so I figured what the heck I'm tired of MDA and I have a EGA card. I adjusted the horizontal as much over as I can and I still can't get it right? Anyone got any ideas maybe a bad pot?  ImageUploadedByTapatalk1371187720.079827.jpgImageUploadedByTapatalk1371187738.047659.jpg ImageUploadedByTapatalk1371187782.108686.jpg 
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too** 
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#2
06-14-2013, 12:33 AM
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That last picture is a rough representation of what the logo should look like but my terminal on windows 7 messes up allot of ASCII graphics...
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too**
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#3
06-14-2013, 10:57 AM
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As an aside, this has been confirmed to happenwith multiple EGA cards, right? I assume your friend didn't also give you the EGA card he was using.
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#4
06-14-2013, 11:52 AM
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No, he used it with a Tandy computer I'm using a western digital paradise card I got that does EGA MDA and CGA. Yes the switches are set correctly I have checked the settings a dozen times
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too** Last edited by josephdaniel; 06-14-2013 at 12:08 PM.
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#5
06-14-2013, 05:51 PM
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Since monitors use a sync pulse to lock the picture, its possible that monitor has a problem there. While a tv has an analog signal and needs a defined sync pulse "blacker than black" as they were defined. A computer with blacker than black can occur in many places, and poor sync will show up differently, but may not appear wavy when poorly locked. I had a c-64 I hooked up to a sony B&W tv on the contrast control, to get better sync I use to poke black color into the screen background, and border color. Without that the lock was not in the right spot, and less stable.
Will that picture lock if you change the screen and background colors? Can you reverse the colors, black writing on white screen? Dead giveaway on a bad sync thing in that monitor.
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Yes you can call me "Squirrel boy"
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#6
06-14-2013, 08:33 PM
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It's easy to do that with a Commodore but with DOS I have absolutely no idea how to do it :P I can see if I can make just a full bright wight screen with black bars running vertically?
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too**
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#7
06-15-2013, 03:09 PM
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Well looking at the picture you posted, it looks to me that the picture is moved over. Could be the monitor is triggering off the wrong edge of a sync, or since the text area will be a nice square block unchanging down the side of the screen, its syncing off something else, like the beginning of the text area. DOS in the 8088 era you use to be able to access the video ram and change the colors. I did it, but I have no idea what it would be like today. I figured you could put something lighter on the screen and see if its triggering in the wrong spot.
Looks like on a long text line, it prints during retrace and smears everything on the line. Does the printing look symmetrical? not too wide? Black bars running vertical would give it a sync option, how about a round ball solid 80% of screen..... I think it could possibly be too short and distorted a horiz scan, it is suppose to be a saw tooth, the horiz osc may be giving a distorted saw tooth.
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Yes you can call me "Squirrel boy" Last edited by Username1; 06-15-2013 at 03:15 PM.
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#8
06-15-2013, 04:38 PM
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The text is symmetrical up until it begins to fold over and come back around. Is it possible that leaky caps in the sync section could be causing this? These monitors were known to have bad caps in them.
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too**
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#9
06-15-2013, 07:00 PM
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It's possible that a capacitor is the problem, but...
The text is lined up so perfectly, but in the wrong place, it seems possible that it's getting the wrong signal somehow. Maybe the wrong polarity. Does this monitor use separate video and H drive and V drive? So, if the signal from the computer is correct, maybe an inverter stage in the monitor horizontal drive input is blown?
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#10
06-15-2013, 07:17 PM
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Could be a cap, buffer, transistor. Does this monitor only handle one kind of signal, I'm assuming its not multi-sync. You may have to get a schematic, and trace through the sync from the input to the horiz ocs, to see where the sync is falling, and why it seems to be in the wrong spot causing the image to shift.
There is a phase shift through a cap, there is a phase shift through an inverter, and if a buffer stage is bad it could cause a late trigger. There are a few possibilities. Time to get out a schematic, and a scope. Take a long look around inside for any physically bad looking parts, like caps, IC's with a hole or a part of it chipped off from overheating, parts running too hot. My tv instructor use to say "look for the part with the green arrow pointing to it." He liked being a smart-ass..... I get a little of that from him...
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Yes you can call me "Squirrel boy"
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#11
06-15-2013, 07:23 PM
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ummm, You lost me at inverter stage.... I'm not very knowledgeable on the names of parts, most of what I know is how to check for out of tolorence resistors, bad solder joints, and failed capacitors, I can also look and see if a part or something is obviously burnt cracked or otherwise broken and look it up on the schematic and replace it if available...
EDIT: This monitor is not a multi-sync (I wish they were) it's a IBM 5154 EGA, Also I don't have a scope I really need one but I just haven't got one yet. Also I don't have a schematic for this monitor but I will look and see if I can find any parts with a green arrow pointing to them... 
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Lebe dein leben für dich selbst **Searching for any all tube or hybrid or color portable sets would consider some early solid state color too** Last edited by josephdaniel; 06-15-2013 at 07:27 PM.
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#12
06-16-2013, 02:30 AM
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Interesting stuff.....
http://abcresellers.com/store/product67.html http://choiceprinters.com/video/oldtech.html Looks like the right old monitor is quite the collectible thing.... http://en.wikipedia.org/wiki/Enhanced_Graphics_Adapter http://www.vintage-computer.com/vcfo...ECD%29-display This was a multi-sync, just not like today's monitors. ------------------------++++++--------------- http://asavage.dyndns.org/Monitors/monitors.html Look up your monitor here, you will see a problem "display shifted to side" might be it.......? a diode..... D401 ....... You'll have to find it..... And you will have to figure out what the specs of that diode are too... I think you should look at this first. ------------------------++++++--------------- The MC6845 was the first graphics chip I learned how to operate..... A very nice chip...! I think you should check the cable between your computer, and monitor to be sure its got all the wires running to the pins used on your monitor, and video card. This may sound silly but I have a number of cables with some unused pins not even there on the plug. If you are not 100% sure on the cable, check to be sure its got wires between all the pins.
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Yes you can call me "Squirrel boy" Last edited by Username1; 06-16-2013 at 02:43 AM.
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