In article <slrnec84dr.kio.don@manx.misty.com>,
don@manx.misty.com (Don Klipstein) wrote:
In article <bdydnSbdqOEXfF7ZRVnyvQ@bt.com>, Grey wrote:
"Fred Mann" <fredmann@bellsouth.net> wrote in message
news:eBdtg.721$%Q6.161@bignews8.bellsouth.net...
Hello,
I have a piece of audio gear which has an illuminated power
switch. The >> LED inside flickers. Should I replace the LED, or is
something else at >> play here? I was under the impression (for no
good reason) that LEDs >> are like light bulbs - either they work
or they don't -- no flickering.
Unless the circuit board/connection was failing, LED's don't
flicker, they just go to "silicon heaven".
Some LEDs of recent years have come from manufacturers shoddy
enough to make some of their clunkers manage to flicker! (I have
seen millions of LEDs, hundreds of different part numbers, with as
far as I can tell all with semiconductor material excluding silicon
for that matter!)
Meanwhile, I would still investigate other explanations, such as
intermittent contact in a bad solder joint or the flickering lamp
being an aged neon lamp! Illuminmated power switches to this day
continue to mostly use neon lamps, and those often flicker when
they have accumulated 10,000-30,000 operating hours where the AC
line voltage is 120 or so (as opposed to 230 or so, where neon
lamps with appropriate resistors can run much longer with merely
fading before they start flickering).
- Don Klipstein (don@misty.com)
Yes, they can flicker if the bond wire to the die is defective. When
the LED heats up, the bond separates. It then cools down and makes
contact again. Then it heats up and the bond separates. It then.....
Al
