improving n64 contrast with psone lcd

[sbf]

Bens trick of shorting out the resistor on the psone lcd is good, but as some mentioned,
the contrast suffers slightly, so why not wire the leds directly to the battery, using a resistor of a different value if you connect to higher than 5v?

This would leave the contrast alone wouldn't it?

What do you think?

[*o*]

i am currently experimenting replacing the resistor witha variable resistor so i can lose a little contrst and increse brightness

[nos_slived]

Bens trick of shorting out the resistor on the psone lcd is good, but as some mentioned,
the contrast suffers slightly, so why not wire the leds directly to the battery, using a resistor of a different value if you connect to higher than 5v?

It wouldn't make a difference, because you would need a higher resistance, and your LEDs wouldn't get brighter.

[sbf]

but doesn't shorting r23 affect the contrast?

Wiring the leds separate of the psone lcd would mean that you wouldn't have to short out resistor r23 to make them brighter, therefore leaving the contrast untouched.

The leds would have the same brightness, but we wouldn't be touching the resistor affecting the contrast.

[*o*]

no. its not the leds that need changing we need to be able to adjust the contrast line manually

[nos_slived]

Having the LED mod has nothing to do with shorting the resistor.

[*o*]

i does...because doing the led mod means it looks crap without the brightness mod

[nos_slived]

But they aren't directly connected, so hooking up the LEDs in a different place wouldn't change anything.

[Gamelver]

i does...because doing the led mod means it looks crap without the brightness mod

that's because leds aren't as bright as the cathode tube that was used to light the screen before

[*o*]

exactly so my theory is rplace that resistor with a 20 mega ohm one and see what happens

[sbf]

well maybe shorting r23 makes the chip controlling it adjust the contrast, and a side effect is the leds get more current,

Maybe a way to test this is to wire the leds separate of the circuit, and try the psone screen with, and without the r23 short, seeing if the contrast does change.


as *o* was saying, we need to be able to adjust the contrast,

I'll have a look later to see if I can get any pinout data on the chips, we might be able to put a variable resistor in place of a fixed one somewhere.

[superdeformed]

well maybe shorting r23 makes the chip controlling it adjust the contrast, and a side effect is the leds get more current,

Maybe a way to test this is to wire the leds separate of the circuit, and try the psone screen with, and without the r23 short, seeing if the contrast does change.

The brightness mod does absolutely nothing to the amount of current or power supplied to the LEDs (or the ccfl tube). It makes it so the LCD gets a little more juice and therefor lets more light through (which is why the contrast gets shot to hell).

[nos_slived]

Once again, "they aren't directly connected, so hooking up the LEDs in a different place wouldn't change anything". It doesn't matter where the LEDs are connected, it has nothing to do with the resistor. If you want to control the contrast more, use a pot on the resistor.

[sbf]

If you want to control the contrast more, use a pot on the resistor.

thats what im saying , that resistor may be responsible for the contrast!!!!!

[*o*]

it needs a 30 mega ohm pot if anyone cares i am picking one up tonight