Turbo Express Composite Out Issues

[ilcmvvm]

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.

[NightWolve]

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.

[thesteve]

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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[turbokon]

Yeah, check pin 20.


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[ilcmvvm]

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...

http://www.amazon.com/gp/product/B0045IIZKU/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

which I have used in other projects with much success.  Any ideas?  Thanks for all the help so far.

[turbokon]

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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[ilcmvvm]

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.

[turbokon]

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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[NightWolve]

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.

[turbokon]

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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[roflmao]

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.

[NightWolve]

So you had to pay for another one or steve managed to alter the circuitry and get the one that you sent him working ??

[roflmao]

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.

[turbokon]

The linked I posted above are the best quality lcd's I've came across so far.


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[deubeul]

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