Sony PSOne LED MOD **HELP** ..

Guest · Post by **Guest** » Sat Nov 27, 2004 5:42 pm

I've followed the instructions on

http://www.doomportables.org/video.html#backlight

to do the LED mod. I decided to go with 3 of these:

http://rocky.digikey.com/WebLib/Chicago ... Series.pdf

I installed them at 3 of the corners (I had to select the corners because anywhere else and it casts side rays at 45 degrees that are visible on the screen!)

I also did the wire jump to make it brighter. Didn't notice any difference.
Here are my problems:

- where do you guys get your 7.5V ?? I'm currently getting it from a spot that always provides 7.5V. But I'm in the process of repairing the LCD screen and want a spot that only provides 7.5V when the PSOne is connected and turned on. Any idea on how to do that?

- I'm using a 22 ohm 1/4W resistor. This sucker gets too damn hot to touch! What resistor do you guys recommend to use?

- Even when the PSOne is off and the LED's are on, it's not very bright. Quite weak actually. Any recommendations?

Post by **gannon** » Sat Nov 27, 2004 5:45 pm

Use a smaller resistor and hook it up to the 5V out on the second 7805

Post by **Gamelver** » Sat Nov 27, 2004 6:00 pm

you could also use a resistor with a higher wattage rating, like 1/2 or 1......

Guest · Post by **Guest** » Sat Nov 27, 2004 6:04 pm

OK..

So I'll get a higher wattage rated resistor and hook it the the 5V. To maintain the same current to the diodes, I'll need an 8 ohm resistor.

That should all be fine with the power and such, but what about the brightness?? Has anyone actually managed to get it even close to original brightness? It's darker than my GBA SP!!

Guest · Post by **Guest** » Sat Nov 27, 2004 6:04 pm

in my last message, I ment same current to the LED's .. not diodes.

Post by **gannon** » Sat Nov 27, 2004 6:08 pm

well....LEDs are diodes

If you use a lower ohm resistor it should get brighter, although if you go over the LEDs specs they'll burn out faster

Post by **SpongeBuell** » Sat Nov 27, 2004 6:16 pm

I'd use the 22ohm resistor to keep the voltage, but ise a 1/2w or, if you have the space, a 1 watt resistor.

Guest · Post by **Guest** » Sat Nov 27, 2004 6:22 pm

Oh.. I got lots of space! All the wires lead to where the old power transformer was.

My concern was that I did not find any 7.2V source on the PCB that is on only when the PSOne is hooked up and on! So it's kinda stupid to have the backlight turn on every time I plug in the power (but not turn on the PSOne).

I assume that the 5V source pointed above is only on when the PSOne is hooked and turned on.. but I have my doubt now (both 7805's read 7.2V when just the power is hooked to them, so why would the 5V out from it be on only when the PSOne is on!???)

Post by **gannon** » Sat Nov 27, 2004 6:35 pm

Why don't you just get voltage from the old transformer's voltage input? I think that was 7.2V too

segasonicfan · Post by **segasonicfan** » Sat Nov 27, 2004 8:46 pm

If you are powering the screen with 7.2v-7.5v (and you should be), use the 7805 voltage regulator (left pin) to get 7.2-7.5v. If you want 5v, use the right pin.

And let me know how the mod turns out, I'm really curious as to how effective it is and I would LOVE to see pics for comparison.

-Segasonicfan

someone · Post by **someone** » Sat Nov 27, 2004 10:32 pm

i will add on what gannon said. LEDs (light emitting diodes) are a type of diode (current can only flow one direction through the device) that is engineered to emit light by the passage of electricity through... a gas?(gannon probably knows!) it goes through something between the anode and the cathode that emits light when electricity passes through it.

Post by **gannon** » Sun Nov 28, 2004 12:09 am

Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor.

I pulled that right off of howstuffworks.com

someone · Post by **someone** » Sun Nov 28, 2004 1:12 am

^what i said

they will burn out eventually i think. the semiconductor eventually wears out, but its in the range of 10,000+ hours <(correct me if i am wrong, i probably am

)

Guest · Post by **Guest** » Sun Nov 28, 2004 9:15 am

gannon wrote:Why don't you just get voltage from the old transformer's voltage input? I think that was 7.2V too

I can't do that because it's dead. There's no voltage there. all 4 pins read 0 volts.

So any advise on where to get 5V or 7.2V from the PCB that will only be on when the PSOne is powered?

I'm shocked that most of the unit is always on and powered when pluged to the wall (connect via battery when in the car!?)

Post by **gannon** » Sun Nov 28, 2004 9:18 am

so it has a quesient draw (bad spelling:P), what's the problem with that?
Also, use a multimeter and find a spot with voltage when it's only turned on.

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Sony PSOne LED MOD HELP ..

Sony PSOne LED MOD HELP ..