psone screen hacking

[Cojiro]

I have read several threads on the LED mod, and lots of them say different things. If I am to believe Ben's book, I should have three LEDs wired in parallel with only one 10 ohm resistor, correct? But then, I have heard that if you wire it in parallel that each LED needs its own resistor, which should be closer to 33 ohms, and that four LEDs looks much more uniform than three. Can anyone help me on this? Thanks.

[limpport]

Yes, having four looks better than just three. It is evened out better, and there is no dark corner. You should have a separate resistor for each LED. The way Ben did it in the book would only work just as good if all the LED's were exactly exactly the same. But because they are manufactured with the teeniest differences, it's not as efficient.

[Cojiro]

So this wiring would be correct? Or do the resistors need to be on the other sides of the LEDs?
When I used the LED wizard, this is what I got

The specs for the LEDs that I am ordering didn't give forward current, they gave reverse current, so I just plugged in the reverse current in for the forward current. Is this the same thing? Thanks

[limpport]

It should be fine. Most LED's have a 20-30 mA forward current anyways.

[Cojiro]

Okay, thanks a bunch.
Also, How much of the top of the board does this mod allow you to trim? I have heard that you can trim everything above the screen, but I have also heard that you can go farther. To fit inside the case that I am planning on using, I need just a mm or two past the top of the screen. How much more of the top can I trim?

[limpport]

You can trim the top down to the red line and you'll be fine. If you are using a dremel, I would recommend sniping off the components that will be in your cutting path. They'll splinter and fly everywhere if you hit them with your dremel.

Picture 4.jpg (74.95KiB)Viewed 8528 times

(Image is from Erlex's tutorial for removing the bottom of the PSone screen board found here.)

[Cojiro]

Awesome, thanks a bunch. I'm pretty sure I saw that tutorial somewhere but I didn't see the red line. Thanks again.

[limpport]

Awesome, thanks a bunch. I'm pretty sure I saw that tutorial somewhere but I didn't see the red line. Thanks again.

Yeah, I added the red line. I posted a link to the tutorial in that post, as well.

[Cojiro]

Oh, okay. Thanks a bunch, that was a lot of help.

[Cojiro]

do you by any chance know how to rewire the volume and contrast controls? i wired it to a pushbutton with what i thought was the right way, but sometimes they don't work, and sometimes the volume up makes the volume go down, same with contrast. anyone know what problem this could be, or how to fix it? the way i have it wired: when you remove one of the tact switches, there are four points (i'm wanting to call them solder pads but i know they're not), one in each corner. i soldered to the bottom left one on each of them, ran the wire to a pushbutton, and then grounded it. anyone know what the right way to relocate these buttons is? thanks

[Cojiro]

This is how I have my volume up button wired, but it's not working correctly.

Does anyone know if this is right and my screen is just messed up, or if it is wrong and how to do it the correct way?
-Thanks

[limpport]

I'm not sure what goes to what around the tact switches, but Erlex's tutorial for removing the bottom part of the screen has contact points on the back of the board that you can solder the switches to:

(again, I hope Erlex doesn't mind that I'm posting his pictures)
http://img200.imageshack.us/img200/1327/img8445r.jpg" onclick="window.open(this.href);return false; <Back of the board
Spots L and M are where you want to solder to.

Refer to this diagram on how to hook it up:


(Photo credits to Erlex)

[ishowernaked]

How big is the screen at it's widest and tallest before you trim it, and after you trim it, just to get some perspective?