Please check my work...screen hack

If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.

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myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Please check my work...screen hack

Post by myersn024 »

Ok. Before I begin, this is all theoretical. The pictures below weren't taken by me and are for demonstration purposes only. I haven't attempted any of this yet, but I think I've got my head wrapped around the process. Please tell me if I'm wrong.

[EDIT] I have actual pictures and stuff from my screen below [/EDIT]

I picked up an Interact 4" psone screen the other day and I can't find a diagram showing where to hook up composite video and audio to the board. However, I think I know how to find the spots.

Below is a picture of the input board of an Interact screen.
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Here's a pic showing where the wires from the input board go to the controller board.
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The red arrow in the picture above is what I beleive to be power since there are only two wires going to it, red and black. This can be tested with a multi-meter either while powered up or just testing for continuity between that part of the board and the dc input plug on the input board.

The black arrows point to what I believe to be the audio and inputs. I'm not 100% sure how to determine if I'm correct other than testing for continuity with a multi-meter.

Finally, there's one lone wire over on the left side (may be a white and black pair, but I can't really tell) that I don't have an arrow pointing to. I believe this to be video, and I beleive this could also be verified by testing for continuity between that point on the board and the composite video plug.

Please tell me if I've overlooked anything. I'm not very experienced with these kinds of things, but I think my techniques are correct. If they're not please let me know.
Last edited by myersn024 on Fri Dec 15, 2006 2:46 pm, edited 1 time in total.
Nucklez
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Post by Nucklez »

That looks fairly similar to the one that I've worked with. I also have a 4" PSOne Interact screen, but your AV board looks different than mine. You better check one thing out for sure though, the +7.5 volt wires were black, and the grounds were red. I'm not sure why they are backwards on mine, but I would test that before tearing into it too much. If you follow my signature to my website and click on the Dreamcast section it has some diagrams of my interact screen.
Image
myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Post by myersn024 »

Those pictures were posted by another use. I haven't torn my screen apart yet because I can't find my precision screwdriver set. I was just using those pictures for demonstration purposes. I'll definitely check out your diagram though. I'm ready to get rocking on my snesp project.

EDIT => The screen that you used on your dreamcast is the exact same one that I picked up Wednesday afternoon.
myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Post by myersn024 »

Ok, here are some pics of the screen that I'm going to use. The first one is before I started taking it apart. It looks like there's stuff on the screen, but it is really a reflection of the acoustic on my ceiling.
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This one is of the front of the screen after I took everything out of the case.
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This one is of the back side of the screen after removing it from the case. There's some white plastic that you can see in the picture that I hope can be removed after I do the white LED mod.
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And finally, here's the screen in action. In this picture it was running off 8.5V from a PS2 power supply. I've ran it off as few a 5V from a PSP charger, but I think it likes the 8.5V better. You can't tell, but I'm playing Need For Speed: Underground.
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I did trace out a few of the wires just to see if I could find them, and I found where most everything will hook up to the small board that has the switches and volume control on it. Nucklez was right, this screen's main power wires coming from the input board are black and the ground wires are red. I'll post up more as I progress. I'm going to try to score a SNES tonight...let's hope the pawn shops have what I'm looking for.
Nucklez
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Post by Nucklez »

Nice, I might try giving it 8.5V instead of 7.5V. It is very washed out at 7.5 when you play anything that has any kind of motion to it. Expecially Sonic Adventure.
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myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Post by myersn024 »

I didn't really notice that the color were washed out. The main thing that I noticed was that it doesn't have really great resolution. Of course, who am I to comlain when I only spent $20 on it. As far as voltage goes, I still haven't decided on how many batteries to use. I'm going to do a little more testing first, but I think that I'm going to use a 6 NiMH pack for powering the whole system. That'll give me a 7.2V nominal rating on the battery pack, and a full charge will be around 8.4V. Considering that I've ran the screen on as little as 5V, that means I should get plenty of use out of a pack with about a 3000 milliamp hour rating, especially since the pack will be "dead" at about 6.5V.
sammy
Posts: 568
Joined: Thu Dec 08, 2005 3:13 pm

Post by sammy »

The LCD panel is by toshiba right? I have the exact same LCD but the pcb is by Goodwell.
myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Post by myersn024 »

I don't have the slightest idea who makes the screen or the board. All I know is that the screen was marketed and sold by Interact. It is a decent quality screen, but if I ever portabilize anything with 32 bit graphics or better, I think I might go ahead and buy a good 5 or 6 inch screen.
sammy
Posts: 568
Joined: Thu Dec 08, 2005 3:13 pm

Post by sammy »

Yeah, the dots are a bit too far away from eachother for really good video quality.

I thought about using an 8' joytech PS2 screen for my next portable. They can input RGB and they're only 150$ new.
myersn024
Posts: 212
Joined: Mon Dec 11, 2006 2:34 pm

Post by myersn024 »

The resolution shouldn't be bad for a 16 bit game on the interact screen, though. Where can you find those 8" screens that you're talking about? Can you get them in the states or only overseas?

*EDIT*
Nevermind. Wal-Mart.com has them.
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