A few questions about the Zenith GC LCD Screen

So I got my Zenith LCD screen in the post, and I thought I'd crack it open and play around with it for a bit. I have a few questions about it if someone could indulge me

First off, here are some pictures:






You may already know, but this LCD (made for the Gamecube) has the same innards as the official PSOne LCD screen - or at least it does as far as I'm aware. But you can see that they have made a couple of minor alterations.

Firstly, you can see that they have had to wire the +7.5V and GND wires directly onto the board (and yes, I checked this still runs off 7.5V), secondly they have soldered a big-ol' 1mF cap over the outlet and GND pins of the 7805 regulator - any idea what they would do that? Isn't there a decoupling cap for the regulator already on the board?

Next question: it's my understanding that you must supply +5V to pin 12 of the (longer of the two) input connectors in order to power up the screen (at least on the official PSOne model). However, on this model the screen powered up whenever I stuck 7.5V across the 7805, no extra wire from the 7805 to pin 12 needed. I can't see any connection that the manufacturers have added to get that 5V connection, and I even tried to add my own 5V connection but that stops the screen from working... Any idea what's going on here?

Last question: You can see from the final pic that the screen works fine with an NTSC N64 system (the lcd is also an NTSC model), but when I tried it with my NTSC SNES I didn't get any picture - is there any obvious reason this would be the case? I was using comp. video for the input in both cases.

Thanks for any help!

 

If it is just the PSOne screen, try using RGBS instead of Composite Video. The N64 will require a mod to use RGB. Anything revision after the NUS-CPU-04 requires Tim Worthington's N64RGB board. The GC needs the GCVideo lite mod board for RGB. Since RGB is neither NTSC or PAL, the screen should display RGB at 50Hz if it is supported.

If this truly is just a modified PSOne LCD, any idea where I can track one down? It would be perfect for my portable GC build.

 

I have now tested it with RGB on my modded N64 and it works great! Haven't tried it with RGB on my SNES yet though.

I bought the LCD off eBay (UK) for £15.

Anyone got some insight on my other questions?

 

I see only 1 on eBay for $108 :/

 

Yeah, I guess I got lucky. The guy was selling it untested so I made a speculative offer and got it. Also NTSC stuff in the UK gets overlooked quite often as most people can't use it.

 

It is a PSone screen. Towards the end of the manufacture, they sold off loads of screens to third party and that's why this Zenith screen is just a re-housed PSone screen.

As I recall, the capacitor is to smooth out the voltage and the screen inputs more than 7.5v in the way they have done it which if I remember correctly is also something the capacitor is for - normally, anything over 8.4v and you'll fry the board.

I suggest removing the capacitor and wiring the screen in the usual manner.

The PSone is a very good small screen however the image looks a bit pixilated due to the anti-glare on the LCD. Remove it and the image is really crisp and well defined and vibrant. Only downside is you'll get reflection so you'll see yourself play the game - but small price to pay.

http://www.bacman.co.uk/home/remove-anti-glare/

Process is simple to do and worth it.

Grab the guide while it is still up.

 

OK thanks for the help

Any idea about the +5V sense though? It's strange that the screen lights up without me needing to add the extra wire (as shown on your website). I can't find any extra wiring that Zenith added so it's a mystery to me. Perhaps there's a spot on the board that is empty on the stock PSOne screen, but has a 0ohm resistor placed across it in this Zenith version? I can have a poke around with the meter to see, I suppose.

 

No idea, if what they did works without 5v to pin 12, fine.