[Cerowrt-devel] semi off-topic: LEDs on WRT1200AC

[Cerowrt-devel] semi off-topic: LEDs on WRT1200AC

[Valdis Klētnieks]

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So it turns out that the Linux kernel totally knows about the LEDs
and how to apply triggers - the apparent failure to do so is because
Linksys used sub-par LEDs that over the years lose luminosity.

Apparently, replacing them isn't *that* hard, but some of the
details are sketchy.  In particular, does anybody know what part number
is a suitable replacement?

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Re: [Cerowrt-devel] semi off-topic: LEDs on WRT1200AC

[Jonathan Morton]

> On 17 Mar, 2021, at 3:24 am, Valdis Klētnieks <valdis.kletnieks@vt.edu> wrote:
> 
> Apparently, replacing them isn't *that* hard, but some of the
> details are sketchy.  In particular, does anybody know what part number
> is a suitable replacement?

What you need to determine is the package form/size and the LED colour.  Probably even the latter is not critical.  Then you can obtain replacements through any electronic component dealer.

Through-hole LEDs will be described by their optical housing dimensions.  Circular ones are typical, so measure the diameter.  Then check whether the top surface is hemispherical or flat.

Small surface-mount indicator LEDs (not the larger ones used for lighting applications) will usually be described by a four-digit package code that is common to resistors etc, and simply describes their width and length.  This shouldn't be too hard to determine.  You then only need to remember which way round to fit them.

 - Jonathan Morton

Re: [Cerowrt-devel] semi off-topic: LEDs on WRT1200AC

[Aaron Wood]

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As they're white LEDs, voltage (well, the current-limiting resistor used)
will probably matter (different color LEDs tend to take different
voltages/currents for the same brightness)

On Tue, Mar 16, 2021 at 8:06 PM Jonathan Morton <chromatix99@gmail.com>
wrote:

> > On 17 Mar, 2021, at 3:24 am, Valdis Klētnieks <valdis.kletnieks@vt.edu>
> wrote:
> >
> > Apparently, replacing them isn't *that* hard, but some of the
> > details are sketchy.  In particular, does anybody know what part number
> > is a suitable replacement?
>
> What you need to determine is the package form/size and the LED colour.
> Probably even the latter is not critical.  Then you can obtain replacements
> through any electronic component dealer.
>
> Through-hole LEDs will be described by their optical housing dimensions.
> Circular ones are typical, so measure the diameter.  Then check whether the
> top surface is hemispherical or flat.
>
> Small surface-mount indicator LEDs (not the larger ones used for lighting
> applications) will usually be described by a four-digit package code that
> is common to resistors etc, and simply describes their width and length.
> This shouldn't be too hard to determine.  You then only need to remember
> which way round to fit them.
>
>  - Jonathan Morton
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>

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Re: [Cerowrt-devel] semi off-topic: LEDs on WRT1200AC

[Jonathan Morton]

> On 19 Mar, 2021, at 6:16 am, Aaron Wood <woody77@gmail.com> wrote:
> 
> As they're white LEDs, voltage (well, the current-limiting resistor used) will probably matter (different color LEDs tend to take different voltages/currents for the same brightness)

Electrically, white LEDs are usually blue LEDs in fact, with the blue light being converted to white by a phosphor layer on top.  They do tend to have a higher forward voltage than LEDs in the green to red range.

Since the original LEDs burned out rather quickly, it might be a good idea to simply double the value of the existing limit resistors.  You won't notice the change in brightness, and the LEDs will last much longer.  And if there *aren't* any limit resistors - well, there's yer problem.

 - Jonathan Morton