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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: ilcmvvm on March 07, 2014, 01:43:34 PM
Title: Turbo Express Composite Out Issues
Post by: ilcmvvm on March 07, 2014, 01:43:34 PM
I just modded my turbo express with thesteve's composite mod to run a larger lcd screen. I managed to safely lift the required pins and ground them. I attached wires to the appropriate pins, added the resistors, and build the amp with a 2n3904 transistor. It appears to work but the picture is black and white. I'm currently sending the composite signal to a normal crt tv before trying to wire up the lcd. Did I kill my turbo express? :( Any help is appreciated.
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on March 07, 2014, 03:21:08 PM
If you're just getting a black'n'white picture, it means you failed to produce a working Chroma signal, but are only getting a working Luma/Y signal. You need to check the Red-Y, Blue-Y and CB pins and their mixing to figure out what went wrong. Recheck everything you did against steve's instructions. I doubt you "killed" anything, but this is tricky and you gotta do everything exactly as instructed because the pins to mix a Composite signal are normally disabled with an Express.
Title: Re: Turbo Express Composite Out Issues
Post by: thesteve on March 07, 2014, 04:35:30 PM
I am guessing your missing CB as any other missing Sig would still produce some color Mixing the resistors up should still show color, just a muddy pic
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Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 08, 2014, 09:09:52 AM
Yeah, check pin 20.
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Title: Re: Turbo Express Composite Out Issues
Post by: ilcmvvm on March 11, 2014, 03:22:59 PM
I managed to get the output to be in color on the tv. Not sure what had a bad connection, I just removed all the wires and started from scratch. Now the issue I have is the LCD will display a good picture for a second then freeze and turn white. This happens on turbo express power and external power to the LCD. Im using this lcd...
which I have used in other projects with much success. Any ideas? Thanks for all the help so far.
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 12, 2014, 12:16:20 AM
It's known that some of these aren't compatible with the TE resolution. I just got these in and they works great. http://bit.ly/1fKxpZB
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Title: Re: Turbo Express Composite Out Issues
Post by: ilcmvvm on March 12, 2014, 02:49:39 AM
I placed an order for one of those lcd screens. Thanks for the link. Oddly enough they look exactly the same. Guess the guts or driver circuits of the lcds are different. Thanks again.
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 12, 2014, 07:14:00 AM
Yeah, it's hard to tell just by looking at the pictures . The description sometime give you a clue on what the internals are.
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Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on March 12, 2014, 08:29:33 AM
Ah, so you didn't order the exact same model as steve's ?? ... Yeah, I wouldn't have risked that for multiple reasons, this and not knowing the thickness of what you're getting, the exact dimensions once you take it apart, etc. Oh well, good luck.
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 12, 2014, 08:59:59 AM
It was a hit or miss. LCD from a vendor once worked now no longer works because they changed the internals.
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Title: Re: Turbo Express Composite Out Issues
Post by: roflmao on March 12, 2014, 04:05:27 PM
Ah, so you didn't order the exact same model as steve's ?? ... Yeah, I wouldn't have risked that for multiple reasons, this and not knowing the thickness of what you're getting, the exact dimensions once you take it apart, etc. Oh well, good luck.
It was a hit or miss. LCD from a vendor once worked now no longer works because they changed the internals.
I can confirm this. I purchased a screen that steve linked to. Sent it to him with my express and it didn't work. Steve's wizardry eventually got one working, but it's safe to say that they are dinking with the internals even if they are selling them on the same auction.
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on March 12, 2014, 04:07:27 PM
So you had to pay for another one or steve managed to alter the circuitry and get the one that you sent him working ??
Title: Re: Turbo Express Composite Out Issues
Post by: roflmao on March 12, 2014, 04:33:01 PM
So you had to pay for another one or steve managed to alter the circuitry and get the one that you sent him working ??
I bought another one.
And hoped it would work. :)
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 12, 2014, 11:08:00 PM
The linked I posted above are the best quality lcd's I've came across so far.
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Title: Re: Turbo Express Composite Out Issues
Post by: deubeul on March 13, 2014, 09:09:56 AM
Thanks for the link, i ordered one hoping this would eventually works. I'm starting to despair having a GT with a rocking big screen one day :mrgreen:
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 25, 2014, 11:12:12 AM
I just received another batch of LCD's from the vendor I posted above and they all work beautifully:)
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Title: Re: Turbo Express Composite Out Issues
Post by: deubeul on March 25, 2014, 10:20:18 PM
Received it too and works perfect, thanks Turbokon! I also received this model that works fine too: http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=271207921520&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on March 26, 2014, 12:59:51 PM
I hope a model eventually turns up that accepts S-Video, or better yet, RGB for this.
Title: Re: Turbo Express Composite Out Issues
Post by: roflmao on March 28, 2014, 01:56:27 PM
I don't know if you remember the 3.5" screen in my Express. There's some room for improvement. :) If these new screens are better, you might as well bring one along to MGC (if you have the time - if not, you can take my Express home with you).
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on March 28, 2014, 03:09:45 PM
I don't know if you remember the 3.5" screen in my Express. There's some room for improvement. :) If these new screens are better, you might as well bring one along to MGC (if you have the time - if not, you can take my Express home with you).
Yeah, I remember yours. I can say this is much better:)
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Title: Re: Turbo Express Composite Out Issues
Post by: roflmao on March 28, 2014, 04:30:01 PM
I don't know if you remember the 3.5" screen in my Express. There's some room for improvement. :) If these new screens are better, you might as well bring one along to MGC (if you have the time - if not, you can take my Express home with you).
Yeah, I remember yours. I can say this is much better:)
Good googly moogly. Sold! :mrgreen:
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on April 13, 2014, 09:54:50 AM
Well, they do exist, 3.5" models with S-Video (+VGA), but they're expensive as hell so far...
The crazy expensive one: http://www.avionicslcd.com/3.5_LCD_VGA/3.5_LCD_screen_VGA_Hand_Hold_LCD_panel_Display.htm (http://www.avionicslcd.com/3.5_LCD_VGA/3.5_Photos/3.5_LCD_Screen_VGA_to_XGA_LCD_iso_view_M.jpg)
And the less expensive one ($185): http://www.purdyelectronics.com/pdf/AND-TFT-35VX-KIT.pdf
That's really too bad, I can't find anything cheaper.
Title: Re: Turbo Express Composite Out Issues
Post by: thesteve on April 13, 2014, 10:53:45 AM
With proper chip data and a jtag all the screens support RGB
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on April 13, 2014, 11:24:44 AM
Are you saying you could tap the RGB+S signal lines somewhere in the PCB of the $20 Composite-only models that you're using, steve ? I figured that you have those complex ICs and they take the Composite signal and immediately convert to digital and off it goes to run the LCD, so I kinda thought it can't be done with those models.
What's jtag?
Title: Re: Turbo Express Composite Out Issues
Post by: thesteve on April 13, 2014, 02:51:39 PM
those ic's in the $20 monitors have svid and rgb inputs, disabled by software
Title: Re: Turbo Express Composite Out Issues
Post by: NightWolve on April 13, 2014, 04:19:58 PM
Aaaaah, I see. There's hope, just won't be easy.
Title: Re: Turbo Express Composite Out Issues
Post by: thesteve on April 13, 2014, 04:56:07 PM
looks like a jtag job
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on June 02, 2014, 10:41:20 AM
Here is another good LCD.
http://www.ebay.com/itm/281114996830
Goods: Fuller images No "AV1" or "AV2" indication showing up Great picture quailty
Bads: No asylic screen for using with the 3.5" TE mod. No setting dials.
Title: Re: Turbo Express Composite Out Issues
Post by: HyperionAlpha on August 04, 2014, 10:50:33 AM
My TurboExpress has the capacitor blues and I've already ordered a cap kit to fix it, but I'm thinking about diving in with a screen upgrade while I have the thing open. I can't find a tut to do this anywhere on the board however, anybody got a linky handy?
Turbokon: what is an asylic screen, why is it needed?? All the screens you linked here look dope but I like that last one for not showing the AV1 etc.
Title: Re: Turbo Express Composite Out Issues
Post by: turbokon on August 04, 2014, 02:15:53 PM
My TurboExpress has the capacitor blues and I've already ordered a cap kit to fix it, but I'm thinking about diving in with a screen upgrade while I have the thing open. I can't find a tut to do this anywhere on the board however, anybody got a linky handy?
Turbokon: what is an asylic screen, why is it needed?? All the screens you linked here look dope but I like that last one for not showing the AV1 etc.
You'll have to remove the old screen and cut the shell for the 3.5" LCD opening. You will need the asylic screen that's comes with the others LCD to make the screen over the 3.5"LCD.
Title: Re: Turbo Express Composite Out Issues
Post by: HyperionAlpha on August 06, 2014, 04:56:39 AM
Ah okay that makes sense then. Might be better off with another screen in that case, even if it has the text at start.
Nobody has a tut for screen replacement, a pin reference chart, anything?
Title: Re: Turbo Express Composite Out Issues
Post by: thesteve on August 08, 2014, 10:26:38 PM
ive done the pin charts, but would have to search to find then now