[Lcdproc] How to turn off backlight of iMON-LCD at shutdown

Discussion:

Bengt Nilsson

2011-02-20 22:20:28 UTC

Hi!

I have a Antec Fusion Remote Blackwith a iMON LCD.
Is it possible to turn off the backlight when I shut down my Ubuntu 10.04?
It is annoying to have it on with the Good-bye message when the system is off.

BN

2011-02-21 15:43:35 UTC

Permalink

Unfortunately, the answer is: not really.

You can configure LCDproc to display the goodbye message, display a clock, or
turn the display off when LCDproc shuts down, and these features work if you're
just shutting down LCDproc. (See the OnExit parameter under the [imonlcd]
section in LCDd.conf).

However, when the machine is actually shut down, the screen ends up getting
reset somehow (outside of LCDproc), and the backlight gets turned back on.

It's a known issue, with no known solution for now.

-Jonathan

----- Original Message ----

From: Bengt Nilsson <bengt.nilsson11 at spray.se>
To: lcdproc at lists.omnipotent.net
Sent: Sun, February 20, 2011 5:20:28 PM
Subject: [Lcdproc] How to turn off backlight of iMON-LCD at shutdown
Hi!
I have a Antec Fusion Remote Blackwith a iMON LCD.
Is it possible to turn off the backlight when I shut down my Ubuntu 10.04?
It is annoying to have it on with the Good-bye message when the system is
off.
BN
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Bengt Nilsson

2011-02-21 16:37:13 UTC

Permalink

Thanks a lot for the information.
Is this problem specific for the iMON LCD?

Post by jk
Unfortunately, the answer is: not really.
You can configure LCDproc to display the goodbye message, display a clock, or
turn the display off when LCDproc shuts down, and these features work if you're
just shutting down LCDproc. (See the OnExit parameter under the [imonlcd]
section in LCDd.conf).
However, when the machine is actually shut down, the screen ends up getting
reset somehow (outside of LCDproc), and the backlight gets turned back on.
It's a known issue, with no known solution for now.
-Jonathan
----- Original Message ----

Dave Liquorice

2011-02-21 18:35:16 UTC

Permalink

Post by Bengt Nilsson
It is annoying to have it on with the Good-bye message when the system is
off.

Define "off". If you mean fans not rotating and power lights off then where
is the display backlight getting it's power from? It shouldn't really be
connected to the very low power 5v rail that is maintained for wake up on
LAN and similar features.

--
Cheers
Dave.

Berend Dekens

2011-02-21 19:55:19 UTC

Permalink

Post by Dave Liquorice

Post by Bengt Nilsson
It is annoying to have it on with the Good-bye message when the system is
off.

The iMon displays are hooked into the cable bundle for the motherboard
to get their juice. So yes, they are getting their power from the low
power rails which are powered even if the PSU is not active (aka all
fans and disks off).

--
Mvg,
Berend Dekens

Dave Liquorice

2011-02-21 21:04:50 UTC

Permalink

Post by Berend Dekens
The iMon displays are hooked into the cable bundle for the motherboard
to get their juice. So yes, they are getting their power from the low
power rails which are powered even if the PSU is not active (aka all
fans and disks off).

So it's a hardware problem not a software one. B-)

I guess it could be worked around in software but as has already been
pointed out the backlight will come back on when the board gets reset.

Simple solution is to move where the display gets it's power from. Shift it
from pin 9 (purple wire, +5vsb) to one of the red wires (+5v) in pin 4 or 6.

--
Cheers
Dave.

Paul Hunt

2011-02-21 22:58:18 UTC

Permalink

Post by Dave Liquorice

So it's a hardware problem not a software one. B-)
I guess it could be worked around in software but as has already been
pointed out the backlight will come back on when the board gets reset.
Simple solution is to move where the display gets it's power from. Shift it
from pin 9 (purple wire, +5vsb) to one of the red wires (+5v) in pin 4 or 6.

You need to use the +5 V standby supply if you wish to use the remote
power on feature.
Some, but not all, machines have a problem in keeping the backlight
switched off after shutdown.

It seems to somehow be related to activity on the USB bus after
shutdown, and is motherboard dependent.

I do not experience this issue on my multi-media system, built on a
Gigabyte motherboard - GA-EP45-UD3

It _is_ necessary do to run lcdproc to turn off the backlight, but it
stays off after power down or suspend-to-ram.

(I had to create a little script for my power management subsystem to
get the backlight to go off at suspend. OpenSuse 11.3)

Paul

Dave Liquorice

2011-02-21 23:03:30 UTC

Permalink

On Tue, 22 Feb 2011 08:39:35 +1000, Paul Hunt wrote:

Only to me and not the list, unless it's taking a while to get through the
list...

Post by Paul Hunt

Post by Dave Liquorice

So it's a hardware problem not a software one. B-)

<snip>

Post by Paul Hunt

Post by Dave Liquorice
Simple solution is to move where the display gets it's power from. Shift
it from pin 9 (purple wire, +5vsb) to one of the red wires (+5v) in pin 4
or 6.

You need to use the +5 V standby supply if you wish to use the remote
power on feature.

Does the OP require that feature? If not it's the simple solution.

Even if he does it's still a hardware problem, just feed the backlight from
the normal +5v and the electronics from the +5vsb.

Post by Paul Hunt
It _is_ necessary do to run lcdproc to turn off the backlight, but it
stays off after power down or suspend-to-ram.

Unless there is a mains power glitch... ie the display gets reset. Software
solutions are just bodges to work around a hardware problem.

--
Cheers
Dave.