Small flat LED replacement

[Fuganater]

So I got a temp probe for my WC setup and the display is blue... boo. I want it to be red but it has this weeeeee little flat LED. I've never seen these to buy.

Can anyone tell me where to get a red one? and how to figure out how much power the current one has and what the new one needs?

Big thanks in advance!
-Fuga

[xr4man]

you can get them from digikey, mouser, or newark. just look for a size 1206, 0805, or 0603 depending on how big that one is.

you will also have to change the resistor that is inline with the led. since blue leds drop more voltage than red leds (usually) you will need a bigger resistor to drop the voltage for the red led.

[Fuganater]

there is no resistor....

[SXRguyinMA]

there has to be one somewhere in the circuit

[Fuganater]

I'll take pictures of the circuit board tomorrow so you can see. Unless its some small crazy one I don't see it.

[slaveofconvention]

It's probably a standard SMD LED - you can measure voltage across it with a multimeter like any other LED - just use the metallic pads on each side as contact point.

SMD LEDs are pretty cheap to buy so you could always buy a few of each possible size and play trial and error. You might want to try soldering a couple to something else though, for practice as they can be pretty fiddly...

[xr4man]

that's good advice. it is really easy to over heat them when soldering and destroy them. i've done that more than once.

if there is no resistor at all in the circuit with the led, then that means the board is putting out the exact voltage the blue led is rated at and you will have to add in a resistor for a red led.

[Fuganater]

Its 3.10v across the LED.

No resistors that I can see.

[xr4man]

i see 8 resistors on that board. they are the small black rectangular parts with white numbers on them.

it appears that one lead from the led is going to the resistor on the far right in the top picture.

[Fuganater]

That resistor says 101. How do I find its rating and where do I find a new one that would work with a red led... which i haven't found yet...