New LEDs barely light up....

Out50Stang

[H]ard|Gawd
Joined
Jun 10, 2002
Messages
1,635
I have a Epox 8K3A board and I changed the front panel LED (the power LED only) with a blue one, and it just barely glows blue :( The LEDs that came with the case however light up perfectly nice and bright. but they are green.

here are the specs on the LEDs I bought.

Product Description

Emitted Colour : OCEAN BLUE
Size (mm) : 3mm
Lens Colour : Water Clear
Peak Wave Length (nm) : 465 ~ 470
Forward Voltage (V) : 3.2 ~ 3.8
Reverse Current (uA) : <=30
Luminous Intensity Typ Iv (mcd) : Average in 3000
Life Rating : 100,000 Hours
Viewing Angle : 20 ~ 25 Degree


Absolute Maximum Ratings (Ta=25°C)

Max Power Dissipation : 80mw
Max Continuous Forward Current : 30mA
Max Peak Forward Current : 75mA
Reverse Voltage : 5~6V
Lead Soldering Temperature : 240°C (<5Sec)
Operating Temperature Range : -25°C ~ +85°C
Preservative Temperature Range : -30°C ~ +100°C


Any idea? I don't have my multimeter with me right now so I can see what kind of voltage im getting. Could it be that I have to change all of them? Justa thought.....they are a little tough to get out as they are glued in, thats the reaon i only changed one...
 
I had it plugged into the "power_led" spot, and it was barely lighting, I checked the manual, and there was a pic, that labeled another spot as "hb_led" I think, it's hard to read. andwyas, I put it there and I was blinded, lol. Ok i'm happy now.
 
Out50Stang said:
I had it plugged into the "power_led" spot, and it was barely lighting, I checked the manual, and there was a pic, that labeled another spot as "hb_led" I think, it's hard to read. andwyas, I put it there and I was blinded, lol. Ok i'm happy now.
watch it.. my mobo feeds the power led 5v
 
ryuji said:
almost any 5mm blue led will work just fine on 5v rail
For a while maybe, but blue LEDs, regardless of size or shape, naturally work best at 3.3-3.7 volts. It's a fundamental characteristic of blue LEDs, and can be explained with chemistry. All you need is a 100 ohm resistor in series with the LED to extend the life of the LED by many years--it shouldn't cost much more than a couple pennies.
 
xonik said:
For a while maybe, but blue LEDs, regardless of size or shape, naturally work best at 3.3-3.7 volts. It's a fundamental characteristic of blue LEDs, and can be explained with chemistry. All you need is a 100 ohm resistor in series with the LED to extend the life of the LED by many years--it shouldn't cost much more than a couple pennies.
most blue leds i have seen require 4.5 volts there is a 5% tollerance on these parts so with 5% added on thats 4.75 soo close to 5 volts by time it dies ill prob be hacking up a new case what supprises me is how the hdd indicator light still works... didnt discover that it gave them soo much voltage til they were doing it for a year and i was rather bored with a multimeter one day
 
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