Sega Megadrive Model II portable - project worklog

[flax]

Ripped apart the screen i have. And I'm baffled. The board doesnt look like anything I've seen on the net. The motherboard is squared and maybe 1 cm bigger then the screen on every side. It has 4 smaller boards with controller things on them.

1 board is simply the plug that plugs in to the playstation
1 board had DCin, headphones out and a powerswitch that chooses between OFF - LCD & console - Console only
1 board has 3 potentiometers whom controll volume, brightness and color
1 board with the playstation A/V out and red/white/yellow for stereo and composite out.

What kind of revision do i have?

Hmm, I realize how that its and 'Innovation Full-Color LCD Monitor'. Haven't payed any attention to the box, hah.

It says on the box:
Fully compitable with PSOne
Switch to display on LCD, TV or LCD+TV
Volume with Stereo Speakers
Built-in Earphone jack
Brightness and Color Are Adjustable
Extra AV plug for display from other machine

Well, there I go I guess I just answered my own question

Has anyone worked with this screen before? Seems like there wouldnt be any problem at all wiring all this together.

EDIT: Hmm, found this now:
http://benheck.com/forum/viewtopic.php? ... 90&start=0" onclick="window.open(this.href);return false;
and a link to the screen:
http://www.dooyoo.co.uk/electronic-gami ... reen/#revs" onclick="window.open(this.href);return false;

[flax]

Got the screen disassembled now.

Here are some pics. Sorry for the crappy quality, it was the best I could manage with my crappy phonecamera

The original backlight bulb. Does all bulb look like this? Looks more like a Fluorescent lamp tube thingy
http://i152.photobucket.com/albums/s186 ... 1257804271" onclick="window.open(this.href);return false;

The LCD, the backlight housing and the plastic sheet that spreads the light
http://i152.photobucket.com/albums/s186 ... 1257804272" onclick="window.open(this.href);return false;

the LCD board
http://i152.photobucket.com/albums/s186 ... 1257804272" onclick="window.open(this.href);return false;

EDIT: Got everything hooked up now works like a charm. I have no backlight atm though. The LED's are on the way.
Will 4 LED's with 3000~5800 mcd and a color of 6000~10000K be fine?

I have a wierd humming sound in the speakers though. It is definitely gound related but I cant seem to find a good ground-spot for the speakers.

Atm the consoles and the screens voltageregulators share ground. If I like scrape the groundwire from the speakers on any ground on either motherboard, I can hear the scraping in the speakers, but the humming never goes away.
The humming is in sync with what happens on the screen.

[flax]

Everything is assembled now. Have to get started on the case now.

Summary:

Sega genesis model 2
Off-brand PsOne screen displaying composite video
3000mAh NiMH battery
Honey Bee 6 Button turbo controller

Ohh, just realized I have to work out how I want to charge it aswell, no biggie. Have to get a matching socket for my charger plug and maybe install a switch.

Video of the guts spread out over my table (have to set up some sort of workbench ):

http://www.youtube.com/watch?v=FXQXjbvP7OE" onclick="window.open(this.href);return false;

And yes my camera sucks, and yes I didnt have sufficent lightning, but its something atleast.

The backlight isnt as bad as it seems on the video. I thought it would look better, but its good enough.

EDIT: the video is to fast hah
When you see the screen fading in and out, thats me turning a pot that was on the original board. I don't understand how that can work :O The LED's are hooked up to the megadrives 7805. I thought that brightness only was controlled by the backlight IE the old lightbulb.

[flax]

Just realized that the screens board have a 7505 regulator on it. Want to try and see if I can run the Sega from this one aswell. Don't quite understand how its hooked up though.

http://i152.photobucket.com/albums/s186 ... 1258501354" onclick="window.open(this.href);return false;
http://i152.photobucket.com/albums/s186 ... 1258501354" onclick="window.open(this.href);return false;

Does anyone have any knowledge on how these switching regulators work? Or know where I can find a datasheet or something of it.

It's labelled: 39-91-7505 C.E.I 0004

[rikitheshadow]

All I know about regulators is they produce a lot of heat, from watching your video I would suggest getting a heat sink for your regulator. The more of a load on one regulator, the hotter it will get, if you intend to have a cooler running portable, I might suggest keeping that second regulator instead of jumping off the one on your screen driver board. That way the load is distributed evenly, producing less heat from the regulators.

[flax]

I have a heat-sink on the 7805 now. Had to drill a hole in it because I ruined the holder thing that was on it. But it's there now. Just ran it for a minute on without for the video.

But the 7505 on the screens board is a switching regulator, it doesn't get warm. Instead of dispersing the extra voltage as heat it flicks the power on and of really fast to regulate the voltage. That way its more efficient than a 7805. Thought that I could save some aH on running the whole system from a switching regulator.

But what ever, this will do Just have to get the case together now. Don't think I'm going to build it out of wood anyway. Mainly because I don't have the needed tools. Been looking at some polycarbonate cases and I think I'm going whit that, much easier to work with. Don't think that polycase.com ships samples abroad though (I live in sweden). Haven't found anything in Sweden either. Have to take a look at Ebay.

EDIT: Any tips on other sites that sell polycarbonate cases? Preferably in Sweden, the ones I've found here aren't big enough Need like 7''x7''x1.5''. It's going to be huge I know ;P

[rikitheshadow]

Maybe have someone order here in the US, then ship it to you?

[flax]

Will try that if I find something good in America.

Not one single case on polycase.com is big enough Any other sites to recommend?