G73SW motherboard

I'm trying to find on the motherboard what has a 12 volt output. I know it sounds stupid but I'm trying to install two LEDs to the exhausts. So far I've done so by connecting each led (3.7v) to each fan that is 5v. It turns on and everything run great but since it's a low voltage the light is kinda dim. Do anyone know where I can connet them that would have a higher output or a lower voltage led? Anything would help, thanks.

 

connect it directly to dc jack, but use an step down transformer to reduce the current to the correct amount.

 

Sounds like a fun mod!

Do your LED's have built in current limiting resistors
(spec'ed for a certain DC voltage)? If so, 12V may
not be the best supply to use. Please list the
specs (voltage, current). Is 3.7V the forward
drop?

If your LED's do not have internal series resistors,
you will need to add one, to use 12V. Assuming you
are using a standard 20mA (max) LED, with 3.7V as
the forward drop, this circuit should work well for you:

(12V)---(230 Ohm resistor)---(LED1)---(LED2)---(Ground)

If you want to make it adjustable, replace the resistor with a
200 Ohm + potentiometer (1K to 5K Ohm). This will let you
overdrive the LED a bit, and reduce it to zero output (5K Ohm pot).

Check your DC brick. On my G74SX, it is 19.5V DC. If the G73SW is
similar, 12V will be on the output of the primary DC-DC converter
(somewhere near the DC jack). If the G73SW is using 12V PWM fans
(4 pin), then you should be able to tap into the 12V line, feeding the
fan. If the unit is using 3 pin fans, then it wont work well, because the
fan voltage is being modulated to control the fan speed. Then again,
that might be a nice feature. The LED brightness will increase with
fan speed. Other options for 12V are the SATA and PCI Express connectors.

Good luck,

Sir Robin