Calling all Hardware Experts--LCD Monitor Problem

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tmtomh's picture
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Now that I have your attention... Wink

Just received this 10.5" VGA LCD monitor:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5114892476

It's got a standard VGA (i.e. PC-style HD15) port on the back, and it came with a power adapter and VGA cable.

I've plugged it into two Macs -- a NuBus Power mac with MacPicasso video card (which has a VGA port), and my Powerbook 2400c (which also has a VGA port, for mirroring).

The monitor powers up to a blank grey screen, and I can see some flickering when I change resolutions on the 2400, but I can't get it to display the Mac Desktop.

As you can see from the pic in the auction, the seller got it to display just fine using Win2000, at what looks to be 800x600.

But I can't get it to work. Using the display mirroring control strip module on the 2400, I've tried everything -- 640x480 at 60 and 67Hz; 800x600 at 60 and 72, 1024x768, etc. Nothing works.

Any ideas? I will email the seller, but I'm 99.9% sure he just hooked it up to a regular PC -- all this monitor supposedly needs is a VGA-capable video output.

Thanks for any help -- or educated guesses -- folks can provide.

Matt

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performaman's picture
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Is there a sticker/label on t

Is there a sticker/label on the back with the maximum refresh rate? And do you have to enable an external monitor in the MacOS as in WinDDoS? I don't remember having to on my 5200's external monitor port, but I could be wrong.

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tmtomh's picture
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D'oh! -- Success (mostly)

Success! (Well, mostly)...

I was going to start packing it up to send it back to the seller, convinced that the video board was bad -- and then, in true 'fritter tradition, I thought, what the heck, let me take it apart and see if I can eyeball a problem.

No sooner did I open it up than I did I see that the video board connector that plugs into the actual LCD panel, was disconnected!

It looks like there's some dried-out adhesive of some sort on the connector, that originally helped keep it secured to the LCD panel--why these aren't locking connectors I'll never know. So I guess it got jostled during transit and came loose. That's why my computers kept starting up okay -- they were "talking" to the LCD controller board just fine. But the controller wasn't talking to the actual display panel at all!

Anyway, it's now good. For some reason I can't get my MacPicasso card to display 800x600 properly. It displays it, to be sure, but the vertical center is off, with the bottom inch of the desktop at the top of the screen, and the top of the desktop starting about two inches down from the top of the screen. I can use the monitor's own controls to adjust it to a point, but not enough. I can further adjust it with the MacPicasso's Control Panel, but when the image is just nearing tolerability in terms of vertical center, the monitor loses sync with the video card.

I'm thinking that perhaps this monitor wants a 70Hz refresh rate (does any video card do that?) -- the aforementioned problem happens at a 60Hz refresh rate, and the next-highest available rate is 72Hz, which causes -- you guessed it -- a loss of sync.

But it runs just fine in 640x480 mode, which is good enough for my intended use of this monitor. In fact, text is actually much more readable at 640x480, which is surprising given the fact that the monitor's native resolution is 800x600 (unless it interpolates 800x600, but I doubt that for a monitor this old).

Final note to CC hackers -- this appears to be a Sharp LCD panel, so I'm guessing that the controller inside will work with a variety of Sharp panels, including perhaps the 8.4" units that are useful for sticking into CCs and making Tacos.

Matt

tmtomh's picture
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To Distill...

...all the verbiage of my last post down --

Does anyone have any ideas on getting 800x600 successfully on this monitor? Any way to force a 70MHz refresh rate from the video card?

Matt

jt
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Nice save, Matt!

Dunno about 70 Hz, the ATI T**D in the 466DA lists 800 x 600 resolutions in 56, 60, 72, 75, 85, 90,100 and 120 Hz flavors, but no 70 Hz.

Have you tried it with a Road Apple or PCI 6xxx/5xxx video out hookup as a control? Could be the NuBus card, not the LCD/Controller, no?

jt :?

edit: the other thing that pops into mind is that an industrial display may be looking for that low ball 56 Hz feed where a consumer display'd need to run at a higher refresh rate.

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tmtomh's picture
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Thanks for the tips JT

The MacPicasso is an impressive card, but a little strange as well. You're right about that, it could very well be the card.

I'm currently on a streamlining kick so I don't have any Road Apples around. But I do have the VGA port on my 2400 -- and I was so excited when the monitor started working that I forgot to notice if it was displaying at 640x480 or 800x600 when the 2400 was driving it. But you can be sure I'll check!

On the refresh issue, there's actuall an option on the 2400's external monitor settings for 57Hz. I'll try that. In addition, I notice that the MacPicasso's Control Panel has a strange "feature" -- when you switch the resolution, it doesn't automatically switch the refresh rate (as Apple's own Monitors and Sound CP does).

So, I will set the monitor for 640x480 at 67Hz in Monitors and Sound (it runs fine in that mode), and then switch the Resolution with the MacPicasso CP -- which will give me 800x600 at 67Hz. Perhaps that will be an improvement over 800x600 at 60Hz.

Updates to follow...

Matt

jt
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67 Hz wasn't listed . . .

. . . in the 800 x 600 choices for the Rage Pro, that seems strange to me now. My money is on 56.6666 Hz Which would be an abysmal refresh rate on a CRT, but probably not all that bad on an LCD. Does the case look like it's for industrial equipment, a CCTV/Security setup or maybe something like an advertising display in a Deli?

jt :?

edit: Is the "NuBus" PowerMac testbed your 7100/700 hack? If so, have you got the A3® video adapter for it? ***

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I believe that most all lcd m

I believe that most all lcd monitors all run at 60hz. Running them at faster refrsh rates isn't necessarly recommended because the hardware is designed to work at 60hz.

Remember, lcd's don't suffer from flicker like crt monitors.

What is the native resolution of the monitor anyway? lcd's generally look perfect only when they are driven to their native resolution. Driving an lcd monitor at a lower resolution is going to cause artifacting to occur (a dark vertical thin (1 pixel) line might appear to be multicolored due to it being forced to interpolate its color on 2 pixels even though its only 1 pixel wide at the set resolution). Its quite noticable on a lot of monitors. Sometimes if you halve the resolution, it doesn't seem as noticable (example: driving a 1280x1024 monitor at 640x480, its close to half) since the pixels are almost a 1 to 2 ratio unlike driving the same 1280x1024 monitor to 800x600 which is closer to a 1 to 1.5 ratio (that .5 is the problem).

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tmtomh's picture
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Resolution...

... is hard to tell. I contacted the manufacturer, and they said the monitor is so old that they have no information on it at all!

If I decide to take it apart again, I'm sure I can get the p/n off the LCD pane and use that to find the specs -- perhaps EarthLCD will have info on it.

As for artifacts, I get what appear to be pixel-interpolation artifacts at both 800x600 and 640x480. These artifacts are inded like vertical lines -- or I should say they're not lines, but they affect text as if there were a tiny vertical line "wrinkle" in certain places.

Interestingly, the location of these vertical "wrinkles" can be changed by adjusting the monitor's "focus" control (one of a number of hard-wired menu options including brightness, contrast, V center, H center and H size). But the focus control doesn't make them go away, only moves them around.

At any rate, they're not very noticeable, and they seem to exist at both resolutions.

And I don't think the monitor's a 1024 x 768 model, as it won't sync with either the MacPicasso or the PB2400 at that resolution. Plus I doubt there was even such a thing as a 10.4" XGA LCD panel before -- what? -- 2002? And from what the manufacturer told me, this monitor is almost certainly older than that.

Matt

tmtomh's picture
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Testbed, and Industrial

The testbed NuBus PowerMac is indeed my Q7100b/G3 hack. Pics of the monitor with the Mac are linked just below.

Can't use this monitor with the Apple POS HDI45 monitor port, for two reasons: (1) don't have an HDI45-DB15 adapter; (2) the HDI45 port on this 7100 board is hinky -- everything looks magenta.

As for the LCD monitor, it's definitely an industrial monitor. It was made by Dolch, which makes them for harsh work environments.

The whole thing is metal except for the front frame, which is plastic. The rear housing screws onto the inside of the front housing. The base is a small, square metal piece with four large mounting holes in it. Welded to that is the cylindrical stand, which ends in a giant ball-joint looking thing. This allows the screen to be angled for optimum viewing, and also tilted side-to-side in case the base can't be mounted on a level surface. The angle setting gets set tight by a decidely industrial-looking screw adjuster. Despite all this, however, the whole thing weighs less than 10lbs.

The back has a small sticker that says, "Property of Gasonics International." It's in remarkably good shape, however. There are a couple of minor scratches on the top of the case, and some easily cleanable sticker residue on the rear. You can check out some pics here:

http://homepage.mac.com/mruben/PhotoAlbum33.html

On the inside, it's very simple and not especially industrial-looking. There's a Sharp LCD panel just like what you'd find on eBay or at EarthLCD, and a VGA controller card (which also looks a heck of a lot like the one at EarthLCD). The controller card is wired to the VGA port (obviously), to the hardware menu control pad on the side, and to a power jack. It's nicely done, but very basic -- really simple to disassemble (and service, which I guess was the point). The menu control pad buttons are a sealed-membrane type deal, and the power jack is a snap-locking XLR-style deal. So I guess in that respect it's pretty industrial too.

I'm just happy to have found a dark-colored LCD monitor that's small (I wanted a frame size noticeably smaller than a 13" VGA CRT), has a standard VGA input, and that cost less than $100.

Matt

dankephoto's picture
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so what's the panel?!?

the LCD model/make, etc.?

dan k

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