tom wrote:
On Apr 28, 3:18 pm, Ken wrote:
mike wrote:
tom wrote:
Hello. I've never done this before so I just want to make sure I'm
doing this correctly. I want to change a three pin multi colour led
activity light on a dvd drive to a two pin blue led. I'm guessing I
need to join the two cathode inputs on the circuit board together?
Makes sense to me but I don't want to screw anything up. Thanks
Look at the circuit diagram or reverse-engineer it.
Tying pins together might work just fine...maybe...or it may let the
smoke out. I can't count the number if times I assumed the designer
was logical and F'd something up.
Depending on how clever the original designer, there's more than one
way to connect stuff. Tying pins together is a risky thing to do.
Might be safer to replace with two blue led's.
Or, since you're throwing away one indication, use one led and forget the
other.
What's the cost of a new drive? How badly do you want the blue light?
The thing has two colors for a reason.
I don't remember the Shakespeare quote, but to goes somehthing
like, "if it bothers you, stick tape over it."
Or just Leave it alone and train yourself to ignore it!!!
If you have to ask the question, leaving it alone is appropriate.
He might also try installing a diode between each input lead and the
controlling lead of the LED. This would provide isolation and possibly
damage to the other control circuit.

Thanks for the replies. There's a schematic on the board and it looks
like this. http://tinypic.com/r/29ynsrq/7 Currently the top three
connections are being used for the led.

Your schematic is missing ALL the critical parts.
What drives the leds?
Likely comes out of some chip somewhere and you probably still won't
know what drives the leds unless you reverse-engineer the circuit and/or
the chip, depending on what documentation is available.

Put two blue leds and be done with it.

I am kinda curious what's so important about this that you'd risk
blowing up the drive??