Hey guys, this is Ben Heckendorn, you know, the runner of the site who occasionally pops up so you know I'm not dead. Anyway, while working on my next ALL-NEW portable system, I made a discovery regarding the PSOne screen!
Long ago I did a LED backlight mod to my screen and I know quite a few of you have adapted it. While it DOES work and lowers the power usage by a lot, it's not very bright.
WELL, NOW THAT HAS CHANGED!
Strictly by accident, while holding the PCB of the screen, I noticed by putting your fingers on certain places it changed the image. The horizontal position, the colors. If I licked my finger and touch the middle of the board, the whole image got way brighter (as you can see, I'm incredibly scientific) I narrowed it down to ONE surface-mount component. I placed the JPG on my website, use this link to find it: [acually, it's right here. -abbibi]
This is the middle of the back of the PCB, and the top of the photo is "UP". Short out that little resistor, capacitor, whatever it is (I have not clue!) with a bit of wire (so it basically "isn't there") and you will see a SHOCKING increase in brightness. The contrast goes down a bit (the blacks are less black, the edges of whites are less sharp) but it's SO much brighter I'm pretty sure you won't care. The brightness control actually seems to DO something now (instead of having to be all the way up, you can now center it). I use a 22 ohm resistor hooked to the 7.2 volts in on the screen, that resistor then goes to (3) 3mm white LED's (Digi-key part CMD204UWC-ND) wired in parallel placed in the lower-left, lower-right and upper-right corners of the screen. It draws 310mA at 7.2v.