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Author Topic: Something isn't right with my LCD screen  (Read 9510 times)
TheIdeaCan
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« on: September 04, 2013, 03:49:52 AM »

So I finally broke down and decided to build a K-Jintiq / Cintriq style tablet using a Wacom Intuos 3 PTZ-930 9x12 and a LG LP150E05-A2K1 LCD screen. Unfortunately, I couldn't get the RM.5451 LCD controller that was used in both previous builds. I don't know if NJYTouch was sold out of them or if that model of controller was discontinued. They just told me it wasn't available. So instead they sold me a B.NTA92C controller that they said would work and is supposedly programed to control the LG screen.

However, when I hooked them up to test out the screen (using the DVI connection), I'm getting a ton of jitter/flicker with equally spaced vertical lines across the screen that is reminiscent of an antique CRT monitor.

* LCD Screen 1.jpg (225.02 KB. 1000x750 - viewed 368 times.)

On top of that, the lines cut through any text/graphics on the screen and there's something funky going on in the lower left corner of the screen.

* LCD Screen 2.jpg (224.4 KB. 1000x750 - viewed 402 times.)

Of course I made the mistake of not fully testing the screen and controller when they arrived as I was still trying to source a new graphics card at the time and any chance of returning either isn't going to happen.

So what are your thoughts? Is the screen fragged or is the controller not programmed correctly or could it be both? I'd like to get going on getting this thing built, but if I can't get the screen to work on it's own without the Intuos thrown into the mix, I'm dead in the water. Any help you guys could offer would be greatly appreciated. Thanks

One last thing to either of the guys from the K-Jintiq build or the creator of the Cintriq. Where did you get your replacement CCFL backlights from and what was the length you used? I was thinking of swapping mine out like you guys did to get the longer CCFL cable (so I don't have to use a CCFL extension cable). Also, does anybody know if the connector NJYTouch uses to connect the LCD controller to the backlight inverter board is standard? I was considering replacing the CCFL with a LED backlight and wanted to know if a LED backlight inverter (is it still called an inverter if it's connected to LED?) would connect straight into it or if they use a different connector.

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Aerendraca
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« Reply #1 on: September 04, 2013, 07:04:49 AM »

Ok, well based on the images you've supplied it looks like the controller hasn't been programmed correctly, i think there was a build a little while ago that reported the same sort of images. You might try downloading a freeware edid viewer to see what settings the controller has programmed, and compare the details with the spec of the screen you have.  Also if this is the issue NJYTouch seem to be pretty good and will probably be able to assist you further.

To be clear, the edid viewer is theory and has not been conclusively used to demonstrate a miss programmed controller yet, but i believe is should work.

As for the connectors, I'm afraid i cannot help since i have not used NJYTouch myself.

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TheIdeaCan
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« Reply #2 on: September 04, 2013, 11:30:22 AM »

Thanks for the suggestion on the EDID Viewer program. According to it, the manufacturer of the display is listed as "ROW" with a monitor name of "Crystal View" rather than it showing up as a LG monitor. I assume that this means the controller was programmed incorrectly? If so, that sucks because I was hoping to not have to wait on another slow boat from China to deliver a Programmer. I just looked on eBay and if I order one today, I might get the programmer some time between September 20th and October 8th.

Any idea whether this one would work with Windows 7 or if I'd have to use Windows XP to program it? I guess I could ask NJYTouch, but they haven't been that quick with responses in the past.
http://www.ebay.com/itm/1-USB-Programmer-for-Burning-DVI-B-NTA92C-LCD-Controller-Board-DIY-Windows-XP-/370855667418?pt=US_Server_Boards&hash=item5658b866da

Also, a question for the guys that have reprogrammed controllers before (preferably those with experience on the LG LP150E5(A2)(K1)). Did the software that came with your controller have the LG panel listed or did you have to use something else? If so, what was it? I'm just thinking that if I have to reprogram the controller, I'd like to get it right the first time if possible.
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Aerendraca
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« Reply #3 on: September 04, 2013, 03:34:07 PM »

The manufacturer name might not be too important as alot of screens can be so similaryly specified that chosing one manufacturer over another is arbitrary, for example on some computer monitors you can access a hidden service menu which allows you to change the TFT panel manufaturer, presumably because the controller was designed to be generic allowing the monitor manufacturer to pick a manufacturer for the actual TFT panel, but at the end of the day it's probably only to make sure the edid info matches up in the computers OS for continuity.

I would check refresh rates, resolution, timings - see if you can find the datasheet for you panel.

Not sure if the programmer will work in windows7 as I have never used one.

« Last Edit: September 04, 2013, 06:12:23 PM by Aerendraca » Logged
TheIdeaCan
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« Reply #4 on: September 06, 2013, 06:08:23 AM »

So I've looked everywhere (not everywhere, but a lot of places) online and can't seem to find a datasheet for the LG LCD screen I'm using. I did find a couple of websites that claim to have it but they want to charge a ridiculous amount of money (one quoted as $800/year) to become a member and you can't view the datasheets unless you pay for a membership. So I honestly don't know what refresh rate and timings are supposed to be used for the screen (perhaps one of the guys from the K-Jintiq or Cintriq builds could chime in on what refresh rate and timings their functional LCD screens were set at?). I do know that the native resolution of 1400x1050 is set correctly in the LCD controller.

As a side note, does anyone have any idea whether you can set a default 180 degree rotation (since the screen needs to be upside-down to fit in the Intuos3 case) and refresh rate when programming the LCD controller? If I could do that, it would save me from having to find a Windows 7 compatible software program similar to SwitchResX for the Mac to set a custom refresh rate to cut jitter and allow me to connect the home brew Cintiq to any computer. If not, what are other people using to set refresh rates on their Windows based builds since my Radeon 7850 seems to only have 60Hz and 75Hz as defaults?

Of course just for grins I checked eBay and it looks like NJYTouch is selling the RM.5451 controllers again. So should I just order a programmer and try to re-program my B.NTA92C controller to work with the LP150E5(A2)(K1) screen or should I buy a RM.5451 controller and ask them to program it correctly this time? I know that in the K-Jintiq build they had to reprogram their RM.5451 to work correctly and after searching the site, it seems that others have had issues with NJYTouch not installing the right programming on their controllers. So if I get the RM.5451, should I also order a programmer as well? Not sure what my best next step should be in getting the LCD screen working right.

In other news, I've managed to get pretty far on the deconstruction part of the build and plan to start a build log shortly to show progress and give others that are considering this type of faux-Cintiq build another resource for info on how to go about putting one together. My solution for stripping the paint off the back of the Intuos 3 cover involved a copious amount of Goof Off "The Ultimate Remover" (not sure if it's a special type of Goof Off or not but it's what I had on hand), a fair bit of elbow grease, and a couple of clean rags. I still need to hit it with some Mothers Mag Polish (great for cleaning the yellow off headlights and polishing small scratches out of clear plastic). I also need to call the US Teko office to order some RF Shielded boxes for the enclosure and inverter. I find it funny that, if I lived in Europe, I could order them online. However, since I'm in the States (the home country for Teko), I have to call and place an order and hope they get it right.

Any continued help you guys could provide on getting my LCD screen working right would be greatly appreciated. I really want to get this thing working so I can finally stop using my old HP TC4400 for illustration work.
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Aerendraca
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« Reply #5 on: September 06, 2013, 10:08:40 AM »

I think it might be time to email NJYTouch and ask them for some advise on this, I'm sure they'll be willing to help you out seeing as it would appear that the wrong screen has been programmed on it. From what I hear there is a lady (whos name I forget) is lovely, perhaps Bernard or someone can refresh my memory - It might even be on the LVDS supplier wiki.

As for rotating the screen 180degs, this one's easy in Win7, Just do [CTRL]+[ALT]+[Down Arrow]. To make it go back again do the same but with the [Up Arrow] instead. Job done!

Regarding buying a programmer vs new LVDS controller, I would still recommend contacting NJY to see if they can offer a replacement, discount or some assistance at the very least.

Apart from this set back it sounds like you're on track though. I'd love to see some pictures of your work so far.
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TheIdeaCan
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« Reply #6 on: September 14, 2013, 11:16:11 AM »

Well after talking back and forth with Sophia at NJYTouch, they're shipping me a R.RM5451 controller board via DHL that is supposedly going to be programmed correctly. They sold me just the board for $20 plus the $17 for DHL (no clue how Hieron got such a good deal from them when he had the programming mishap on the K-Jintiq build) and I'm really hoping that I'm not going to end up regretting not ordering a programmer. Fingers crossed it will work fantastically the first time it's hooked up.

On another note, I've been taking some pictures of the build so far and plan to start a build-log on here once the new controller shows up.
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bernard
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« Reply #7 on: September 14, 2013, 02:13:55 PM »

Can you dump the EDID information here? If I understand correctly, your LCD brand and model is:  LG LP150E5(A2)(K1)  right?    Some folks found great sites to look for datasheets, maybe you'll get lucky.

When you bring the OSD menu on, does it have the same artifacts?  (This can help tell us where in the pipeline stuff fails).

B.
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TheIdeaCan
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« Reply #8 on: September 26, 2013, 02:46:36 AM »

So I got the new controller about a week ago and the initial problem is completely gone. I don't know if it was a defective or improperly programmed B.NTA92C controller board that NJYTouch sent initially, but the new R.RM5451 board works like a charm. It still cost me $37 more than it should have, but at least the screen works now.

With that problem fixed, I was able to make a big jump in the build progress and have the entire project about 98% completed, but now I've got new problems to deal with. Running the monitor at the default 60hz causes a small amount of jitter. It's not an insane amount on most of the screen (though it is more pronounced by the backlight where it seems no amount of shielding will fix it), but enough to make it rather annoying. I've definitely been spoiled by the zero jitter I have with my tablet PC. So I downloaded Powerstrip to see if I could find the sweet spot refresh rate that will drop the jitter to almost non-existent or at least tolerable on all parts of the screen.

This is where the problem began. I think I can officially say that I HATE Powerstrip and would happily throat-punch the developer if I ever saw them on the street. For some reason, Powerstrip initially decided to drive my monitor at a little over 78hz as the default refresh rate rather than the 60hz or a little under it should have started with. So I fiddled with the settings to drop it down to around the 56hz-58hz range that seemed to work for others using this screen. Everything was going great as I was trying to dial it in to remove the jitter. Then Powerstrip decided to start pissing me off. The monitor worked fine at 58hz the first time it was there, but when I changed it to another frequency and then changed it back, it was suddenly "Out of Range" and caused my graphics driver to crash. After this, nearly every adjustment I made to the settings would cause my brand new ATI graphics card to crash. I even tried uninstalling and re-installing Powerstrip to no avail. The only way I could fix it was to yank the dvi cable out before it crashed the computer again, delete the pstrip.ini file and start over. Of course, now it's trying to drive my monitor at a little over 80.4hz as the default (even though the maximum is supposed to be 80hz). Please tell me there's another option for Windows users to change their refresh rates other than Powerstrip because the jitter I get at 60hz is still to much to be workable and everything I've tried in Powerstrip makes the problem worse rather than better?

The other problem I'm running into is cursor alignment. The Wacom utility for mapping an Intuos 3 outright sucks compared to the calibration utility for tablet PCs (and I'd assume Cintiqs). No matter what I do, I get a variable offset from where the pen is to the cursor depending on where on the screen I'm pointing. If I use the default "Full" option the cursor is consistently offset 1/4" below the pen on all of the screen. Setting it to "Portion" and trying their "calibration" tool, I can get it so that in some places it's lined up perfect, but in others it's either to the right or left by about 1/4" and up or down by about 1/8". Is there any way to trick the computer into thinking that the homebrew Cintiq is either a real Cintiq or a tablet PC monitor so that I can use the tablet PC calibration program that uses the four corner points instead of the top left and bottom right to align things?

At this point, dialing in the last 2% of this project through software and drivers is taking longer than it took to complete the other 98%. I could probably deal with the jitter I'm getting when running the monitor at 60hz refresh rate if the cursor was lined up correctly, but with both problems combined I'm seriously questioning my decision to build this thing when I could have bought a used Wacom 12WX off eBay or a new Yiynova DP10U for about the same amount of money.
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bernard
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« Reply #9 on: September 26, 2013, 02:45:25 PM »

Some people don't realize the complexity associated with a build. Nobody (on this forum) said it was going to be easy, on the contrary. You seem very frustrated going through all that pain. I am sorry to hear that. Yes, getting an off-the-shelf product is a much better choice for someone that do not want to tinker -- especially if the price & specs is acceptable! The reason this whole forum started is because Wacom was about the only option at the time and the price, even for the smallest Cintiq, was just outrageously high.

Powerstrip can create a monitor .inf file that contains EDID-like information (including the refresh rates) to associate with the monitor.  If that got "installed" then I guess you need to find that information within windows (I think it is in the registry, not 100% sure) and reset (delete) it so it start auto-detecting it again and go back to the 60Hz default.  I do not understand Powerstrip and monitors enough to tell you where is that information and how to delete it. 

Have you tried booting Windows in "safe mode"?

Have you went to the "Device Manager", under "Monitors" and try to delete all monitors defined there?

Please don't throat-punch the Powerstrip developers (Entech), as it is about the only tool that offer this type of functionality on Windows. Yes, it is quite weird to deal with this software, it is quite "hacky" and very system-intrusive. You can easily get into a dead-end situation. I have no clue why it would suddenly driving at 80.4Hz.

Your "ATI card" is crashing?  You mean its driver, right? Not the actual "card", I assume. Getting a blue screen of death I suppose?

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bernard
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« Reply #10 on: September 26, 2013, 05:00:54 PM »

if you have issues seeing an image, you might think about setting up a remote desktop/vnc/"log me in" (would be the easiest) access so you can do stuff while it is connected but without the screen working.  Of course if your system completely hangs (because of your ATI card-related crash) then it does not help.
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TheIdeaCan
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« Reply #11 on: September 26, 2013, 07:04:23 PM »

Well it always seems to be the last 2% of any project that gives me the most difficulty (usually due to using software that I'm unfamiliar with and can't get to work correctly) and I generally don't mind tinkering. I've got a CNC Sherline mill that has been almost working for about 8 months now and a fully custom electric guitar I built from the ground up that has needed to be rewired again for nearly 2 years now. So I'm no stranger to tinkering and almost completing projects. I won't mention the motorized bicycle I've been working on for 4 years or how long the restoration of my 1971 Honda CB100 has taken so far. The DIY Cintiq is something I desperately want to add to the completed pile.

It just makes me kind of wish that SwitchResX was available for Windows users since it seems no one has had any issues using it to change their refresh rates in their Mac-based builds. Visually and functionally (physically speaking) the homebrew Cintiq I've put together is exactly what I envisioned when I started the build. The problem lies in getting it to work properly when connected to my computer.

I did find that I should be able to theoretically use the Tablet PC calibration utility if I set the homebrew Cintiq as my primary monitor. The problem I'm running into with that is getting it to work properly since the screen needs to be upside-down to fit in the Intuos case. When the utility starts it automatically "corrects" the rotation of the screen to standard landscape. This results in both the screen and digitizer being 180 degrees in opposition to each other and clicking on the upper left alignment crosshair (that is now in the lower right) does nothing nor does clicking on the opposite corner of the screen. So I'm not sure if it's going to be of any use to help get my cursor in alignment with the pen. Any suggestions on alternative calibration utilities?

As for Powerstrip, I've honestly considered learning how to write my own .inf file for the monitor rather than use it. I understand that it's a rather powerful piece of software that has a lot more functionality than just adjusting refresh rates and can easily "break" a computer as I've experienced with the constant crashing of my graphics driver. I just wish EnTech (or any other software company) made a streamlined version of the software for Windows users that only deals with refresh rates. Especially since they want to charge $30 for the program and it isn't even working correctly "out of the box". Each time that Powerstrip has crashed my driver, the only way I've been able to avoid a BSoD is to yank the DVI cable out of the monitor to disconnect it from the computer and delete the pstrip.ini file (that contains all the custom EDID information and .inf files) to start over. What is truly frustrating me to no end is that it is consistently trying to drive the monitor at higher and higher default refresh rates when it auto-detects my screen and I don't know why. Especially when the EDID information for the monitor states that the maximum vertical refresh rate is actually 75hz and the maximum pixel clock is 130Mhz, but Powerstrip wants to default to a little over 80.4hz vertical refresh rate (last time I tried it) with the pixel clock set at a little over 150Mhz. Who knows, the next time I use it, it might try to default to around 81hz. On top of this, any changes to the refresh rate (that it seems I can only do through creating a custom resolution) doesn't really do much to improve my jitter over what I'm getting at standard 60hz refresh rate and Powerstrip turned off. If anything it only makes my jitter worse or it stays the same.

I kind of wish I knew before I bought the ATI HD7850 card that only NVidia cards offer the ability to set custom refresh rates in their software. On the other hand, I've considered switching over to a LED backlight (even though it will cost me more money and I've already spent more than I wanted to on this build) to see if that will remove the jitter I'm experiencing and allow me to just run the monitor at standard 60hz. I seem to remember reading in another build on here (can't remember who's it was offhand) that switching their LCD screen (I think it was a LP150E05-A2K1 like I'm using) to LED backlight resulted in either zero or nearly zero jitter for them. I just don't know where the best place is to buy a 310mm strip of LED backlighting with a LED "inverter"/driver board that will work with the NJYTouch controllers and won't cost an arm and a leg. Any suggestions?

BTW, thank you Aerendraca and Bernard for the help and suggestions you've offered so far. I really appreciate it.
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bernard
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« Reply #12 on: September 27, 2013, 04:34:27 AM »

LED:  try with the backlight unplugged to see if that is the cause of the problem. With a little luck, it will stay "on". (watch the led of your LVDS board to see if it behaves normally).  Prior to do that, attempt to "duplicate" your display to another monitor (so you can see the image somewhere!) -- beware to keep the resolution of the LCD intact else you will void your test.  First try to duplicate the display with the backlight ON to check that the problem is still there, then restart the whole thing but without the backlight connected.

My little finger told me you were a tinkerer in the heart.  Let's just say that you had a "momentary lapse of reason". :-) P.F.

MacOSX is a unix operating system and *by definition* it is much easier to deal with drivers (or anything -- internally everything is built "simpler" than Windows -- like everything) -- so it is no surprise that tweaks are easier to deal with.  To me, Entech (Powerstrip) is doing Windows Voodoo magic. They somehow managed to intimately know about lot of graphics cards -- it is no surprise that it causes crashes. Especially with newer graphics cards.

For the .inf:  You can just open the .inf that was generated and just tweak it yourself. 

btw, you can try to lower the refresh rate as well, even a small difference (like -0.5Hz) can do wonders.
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TheIdeaCan
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« Reply #13 on: September 27, 2013, 06:59:24 PM »

It wasn't so much a "momentary lapse of reason" as much as general frustration with the software. When using a program that has the power that Powerstrip has over your computer, you would think that using the same settings would cause the same results. What has caused me to be so flustered with Entech is that setting my refresh rate to 58hz would work the first time, but if I changed the refresh rate to around 61hz and then went back to 58hz (with all the other numbers the same as they were the first time I was at 58hz) my monitor was suddenly "Out of Range" and my graphics driver would crash. Even though everything was the same as it was when it worked the first time. What baffled me even more was setting the refresh rate to 60hz would work. However, if I dropped it to 56hz where the monitor would work and then increased it to around 59hz, it would suddenly put the monitor "Out of Range" and my graphics driver would crash. It seems that no matter what I do with Powerstrip, it's almost like the software has it out for me to prevent me from making any progress in reducing my jitter. I'll have to see if I can save off a custom inf file from Powerstrip and then just tweak the file from there instead of messing with Powerstrip any more.

I unplugged my backlight and set up the two monitors to duplicate my display and I'm still getting nearly the same amount of jitter when driving the screen at 60hz with Powerstrip off. So it appears that my problem isn't the backlight as much as the LCD screen itself. I still think the CCFL may be aiding in the jitter a little, just not as much as I initially thought. The strange part is that the worst of it is on the side of the screen where there isn't a backlight or any row/column drivers sticking out. This makes me think the problem must originate with the monitor refresh rate frequency (which I was hoping wouldn't be the case). I must admit that a part of me has considered buying a duplicate LCD screen off eBay to see if my jitter is really a result of variations in manufacturing of the screen itself. Especially since others have reported using the same model LCD and gotten almost zero jitter before they even did much shielding.

Of course, even though I'm almost finished with this build, a part of me has considered trying a new build with a 12.1" or 13.3" tablet PC LCD screen and digitizer (preferably one of the ones that support USB through I think it was pins 1,3,4, & 13) connected to an LCD controller board. From what I understand the tinkering needed with those has more to do with using a soldering iron and installing the correct Wacom driver(s) rather than chasing jitter bugs and cursor misalignment.
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bernard
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« Reply #14 on: September 27, 2013, 08:15:45 PM »

yeah, using a tablet PC with its intended digitizer strapped to it augments the chances that you don't get any jitter.

BTW, in your build, you carefully grounded everything, right?  you want the energy to flow back to ground -- not go in mid-air and interfere with your pen!

Forgot to ask at the beginning, but if you turn OFF the LCD completely, (but leave it there) -- do you experience jitter?

In PowerStrip, did you play with the dialog that you can interactively change the settings live (you see the big 4 arrows buttons in there)?
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