Logitech M305, optical LED went amber.

[goontron]

I don't even know where to begin with this one.
Its a constant amber color. It doesn't vary with temperature or use. Still works on white or yellow surfaces, but that's it. The LED package isn't yellowed or burnt.
It seems like the phosphorus is poisoned or something. Anyody got any explanations? Seen this before?

I'll post pictures of the inside once i find my jewlers screwdriver set..

[stj]

Re: Logitech M305, optical LED went amber.

if it is phosphor-doped UV or blue die then it could have cooked the phosphor.
but why the hell use that tech for red of all colours?

[redwire]

Re: Logitech M305, optical LED went amber.

I would say it's a red led that got zapped from ESD. I have seen that damage an LED and the colour shifts and it's dimmer.
Or the bonding wire has lifted and made a current hot-spot which roasts part of the die, and you get shifted colour.

Logitech M305 probably uses (looks like) Avago (Broadcom) optical mouse sensor. Maybe check the part markings. https://sensor.fyi/list/
Avago spec a 5mm red LED 634nm for their sensors. Amber is around 620nm, IR LED's are around 940nm.

ADNS-3050 is an example.
ADNS-6010 is a laser type, but still red.

[goontron]

Re: Logitech M305, optical LED went amber.

^ Hmm. I wonder if swapping it for a 640nm LED would work. 620nm does!

[goontron]

Re: Logitech M305, optical LED went amber.

The sensor is an ADNS-5095. Opening it up i found some black oxidation on the leads of the LED, near the package. I think redwire is right, its been overheated.

[momaka]

Re: Logitech M305, optical LED went amber.

Wowza.
First time I see a mouse and an LED fail like that. (Most LEDs I've cooked - when I was younger and still learning electronics - just ended up burning until they got dimmer and dimmer.)

... then again, most of my mice are with a ball. No red LEDs or lasers.

[RJARRRPCGP]

Re: Logitech M305, optical LED went amber.

Wowza.
First time I see a mouse and an LED fail like that. (Most LEDs I've cooked - when I was younger and still learning electronics - just ended up burning until they got dimmer and dimmer.)

I would think that LEDs with a missing phosphor, would be bluish or purplish!
(Not HPS-like amber)