Video display Gods, please help!! Industrial CRT conversion.

[fastline]

OK, I have been in here before asking about this and got a bunch of good info to at least better understand some things.

What I have before me is a 9" CRT that is on its way out or at least needs fixed. The screen is overly bright with some horizontal lines. However, I do NOT want to even mess with it. It needs an updated display. The current CRT is monochrome.

I recall that someone taught me about TTL and how that is vastly different than 'VGA'? Or other technology. There was also a sync frequency I believe that was probably different.

Now, on this machine, there was a color LCD option so there is a possibility the video output and connector are the exact same and the display unit is different, meaning there is hidden potential. However, the OEM made their own "Honda" connector for these, so all the wires would have to be determined and converted to a proper DB connector.

I would like to discover how to use the scope to determine what I have? If it is TTL, should I not see some square wave action? Then ID'ing the rest of the wires.

I did find and purchased an "XVGA" converter box that was specifically designed to convert stuff like this. In either case, I still have to convert to a DB connector for it but I feel these converter boxes are wildly overpriced for what they are. I plan to go open the one I have to see what is going on there. Would sure like to find someone very sharp on this stuff. I am pretty clueless when it comes to video.

 

[rjenkinsgb]

There are dozens of different proprietary interfaces on old CRT-based machines.
Commonly they have TTL sync lines and 50 or 75 ohm video signals.

VGA is generally similar electrically but PC monitors tend to use higher refresh rates. Early gear tended to stick with broadcast TV standards.
You need to find out what the line and frame rates are in addition to signals and levels, to work out what may be compatible in standard monitors.

The symptoms you describe are typical of a monitor in need of a new set of electrolytic caps.
However if you do not want to mess with it, I'd highly recommend Tsubis in Germany - they can supply monitors with the correct inputs and bezels to be a direct swap in a lot of machines.
https://tsubis.de/en/

We've used them a few times for replacements when the originals are beyond practical repair due to age and lack of parts.

 

[fastline]

Yes, I know the CRT can be fixed but its old tech and an LCD is easier to look at all day.

I know there are several solutions for retrofit but the second you say "industrial", the price goes exponential. How someone can charge a grand for an LCD today is beyond me.

I am trying to figure out how to utilize my scope to identify what I have now. It would come as a shock to some but there is ZERO published info on these systems. There will be no looking up of a technical specs.

 

[rjenkinsgb]

there is ZERO published info on these systems.

Some makers give connector pinouts in the installation manuals for the gear.
Not always, but they are not that rare.

The installation manuals themselves may be rather hard to locate, which is another problem.

What is the actual machine or control system in question?

 

[mbarazeen]

Since the existing CRT is monochrome and option available for color monitor, the signal most probably be a composite video signal. a LCD display with video input should work without any issue. If the signal is RGB like in VGA out, the option to use a convertor should work. if the frame size will be slightly different, the portion of screen would be blanked. some convertors have option to change the size too. Recently I purchased one on ebay for very cheap.

 

[Ian Rogers]

I thought old industrial CRT's were composite signal.... I had two I converted to run on the old speccy in monochrome... If your monitor has a coaxial connector or a 9 pin din, then you can get a cheap reversing monitor... These usually have RCA sockets... Mine was a 10" rack mount CRT..

I had a small pic16F84 progam witten by a Russian guy ( can't remember the link ) that converted RGB ( digital ) into composite monochrome...
We had to run the pic ( normally 4Mhz) at 10Mhz to get the full screen...

I may be barking up the wrong tree here, but you should have posted a picture of the old CRT...

 

[unclejed613]

there were (in order of adoption) analog composite video, monochrome TTL, monochrome Hercules TTL (different sync frequencies than the standard mono TTL, with limited bitmapped graphics), CGA/EGA compatible TTL monochrome (RGB lines decoded by a resistor string to give various grey scale levels for the colors), VGA monochrome (15 pins, usually used the green video channel for greyscale).

 

[rjenkinsgb]

there were (in order of adoption) .......

And they are just the PC standards...

Early Industrial gear with video displays often had totally unique connections even if the scan rates were standard.

That's why it is useful to know the make and model of the equipment involved, on the offchance there are installation or service manuals in existence that give some clues.

 

[unclejed613]

IIRC, there were also some that fed composite video through a db9 connector.

if the OP is still around please identify the monitor by make and model....

another thing that was common was the use of serial terminals, so it could be a terminal with an RS-232 interface. in any case, the symptoms described in the OP sounds like bad electrolytics in the video amp. i used to do total recaps for old monitors and terminals.

 

[fastline]

Well, here is where I am at. On two machines, which use same brand and similar series controls, it appears there are reasonably priced aftermarket LCDs with the correct (Honda) connector and 24V input and I learned that simply changing a parameter in the control will output in color!!! Still ridiculous price for a tiny LCD but I can survive with it.

On another machine, I opened the machine and took the connector apart to see what I had. That one has a DB15 connector and I am now wondering if that one may have a video format that a PC monitor can work with. I think it was common for these guys to use a standard connector but change the pinout (maybe). It appeared there were 2-3 more wires in the plug on the supply cable side than the monitor cable side. On the supply cable, there is a red/green/blue wire. I am hopeful!! Going to see what I have for monitors with DB15 input to see what it does but can someone indicate how to use a meter to determine the pinouts and HF and VF?

 

[Nigel Goodwin]

Well my daughter (who's over from the Netherlands this week) was having a good moan today about lack of updated software for old machines. She's a chemist who works at a University, and the machines in question cost in the millions, and are controlled by PC's. The software will only run under Windows XP, and on suitable XP era hardware - so they keep buying up old XP machines, and storing them for future use.

You'd think it's be worthwhile to create updated software for the machines, as they work perfectly and are obviously stupidly expensive to replace - so I imagine you could sell an update for a pretty decent price.

 

[unclejed613]

so, i took what scant info was available in this thread, and looked up "honda video connector" and what i found was a pinout for a "FANUC" CNC machine's monitor. not much other info available, but it seems to be analog and not TTL, , so it's most likely a VGA monitor with a proprietary cable. for most OEMs, there's no sense in reinventing the wheel. yes there are some really crazy video standards out there, but most of those began to disappear after VGA and SVGA were standardized. the ones you would really be hard pressed to find a compatible monitor for would be a few monitors that used oddball interfaces, like ECL, differential analog, RGBVH BNC cables, etc... there were some "two-page" displays made for Apple machines and SUN workstations, and they used the large 2-row DB15. i really liked the NEC multisync monitors, since they could be driven by everything from IBM mono TTL to VGA, and may have even had a composite video input. i kept a couple of them around for testing, since you never knew what was in a PC you were repairing until you got it open. it was definitely better than keeping "one of each" on the shelf.

 

[Ian Rogers]

You'd think it's be worthwhile to create updated software for the machines, as they work perfectly and are obviously stupidly expensive to replace - so I imagine you could sell an update for a pretty decent price.

Have you looked into ReactOs… For XP lovers!! https://www.reactos.org/

 

[fastline]

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so, i took what scant info was available in this thread, and looked up "honda video connector" and what i found was a pinout for a "FANUC" CNC machine's monitor. not much other info available, but it seems to be analog and not TTL, , so it's most likely a VGA monitor with a proprietary cable. for most OEMs, there's no sense in reinventing the wheel. yes there are some really crazy video standards out there, but most of those began to disappear after VGA and SVGA were standardized. the ones you would really be hard pressed to find a compatible monitor for would be a few monitors that used oddball interfaces, like ECL, differential analog, RGBVH BNC cables, etc... there were some "two-page" displays made for Apple machines and SUN workstations, and they used the large 2-row DB15. i really liked the NEC multisync monitors, since they could be driven by everything from IBM mono TTL to VGA, and may have even had a composite video input. i kept a couple of them around for testing, since you never knew what was in a PC you were repairing until you got it open. it was definitely better than keeping "one of each" on the shelf.

WOW! Where did you find that and where can i get those honda connectors to make an adapter? Any chance the frequencies will work w a std monitor?

 

[ronsimpson]

Any chance the frequencies will work w a std monitor?

Did you find the horizontal and vertical frequencies?
Where are you? I wish I was there. A minute with an oscilloscope and many questions are answered.

 

[fastline]

Well..... OK, on one machine it 'appears' to be pinned correctly per VGA pinout but the gender is wrong!!! lol So I will see what I have for DB15 connectors or see about a gender changer cable. On the display for it, I measured 60hz on the vert and 31khz on the horizontal. I have no idea if that is exactly right as I used my Fluke mutli with graphic display rather than scope.

The other monitor was too hard to determine. Per the post above, the connected pins look correct that it could be right and I need to convert the connectors but it would be nice to know if the frequencies will work. When we tried to test HF and VF reference to ground, they read 0hz.

 

[Nigel Goodwin]

Have you looked into ReactOs… For XP lovers!! https://www.reactos.org/

I can't say I've ever heard of it, and I don't know if it would help as they seem to need the old XP era hardware as well.

But I'll certainly download it and have a play

 

[ronsimpson]

60hz on the vert and 31khz

That is good news. VGA will do 31500 x 60 There is a good chance a VGA monitor will work. The vertical size might be wrong but ....
Most new TVs have a "computer" input that is VGA. I think many TVs are smart enough to auto fix the V. size problem.
Just try it!

 

[fastline]

Ha, I realized this morning why the other one did not test right. I had not fully turned the machine on so the monitor would not have had an output....lol

If that one tests within range, I will see if I can make an adapter and try another monitor on it as well. I had a monitor there for testing but did expect the gender problem on the first one.

 

[Nigel Goodwin]

Most new TVs have a "computer" input that is VGA.

Quite the opposite, most 'old' TV's (Plasma/LCD) had VGA inputs, new or recent ones don't any more - any remotely modern computer will have HDMI, so no need for VGA.