Cameras not working on XO-1s

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Cameras not working on XO-1s

Christoph Derndorfer-2
Hi again,

another issue we encountered during today's workshop session was that on 3~4 XO-1s the camera didn't work (all machines are running 12.1.0 with the associated firmware).

The effect in Record is always the same: a grey still image. However when running the hardware self-test 2 of the machines passed the test even though the camera output on the display was total noise. With the other machine or two the self-test failed.

Since I've never seen issues with the camera before I was wondering whether there was anything we could try beyond verifying that the camera connector is in place (as described at http://wiki.laptop.org/go/XO_Troubleshooting_AV#Errors_communicating_with_the_camera)?

Thanks,
Christoph

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Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]



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Re: Cameras not working on XO-1s

James Cameron-2
The firmware self-test of the camera does not "fail" every symptom, it
can't tell if the image is good, that's up to you.

Also, the firmware self-test does not use the camera in the same way
that Linux can, so the symptoms can be different.

If you need to diagnose beyond checking the camera connector, the next
thing to try is swapping cameras.  Please use electrostatic discharge
precautions.

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Re: Cameras not working on XO-1s

Gary Martin-2
In reply to this post by Christoph Derndorfer-2
Hi Christoph,

On 30 Jan 2013, at 20:02, Christoph Derndorfer <[hidden email]> wrote:

> Hi again,
>
> another issue we encountered during today's workshop session was that on 3~4 XO-1s the camera didn't work (all machines are running 12.1.0 with the associated firmware).

Random FWIW, on my XO-1 B4 the camera stopped working (black screen). In this case, it was due to an overly short flat flex cable from the camera to the motherboard, where twisting pressure (opening/closing) on the case could pull the flat flex cable out of the socket enough to loose connection (I think movement of a usb key in one of the two right sockets could also trigger it). In my case sometimes slightly squeezing the case by the camera triggered the camera back into life for a short while. In the end I opened the unit up and firmly reseated the cable. It's been fine since then.

This issue was subsequently fixed, but I'm not sure when.

Regards,
--Gary

> The effect in Record is always the same: a grey still image. However when running the hardware self-test 2 of the machines passed the test even though the camera output on the display was total noise. With the other machine or two the self-test failed.
>
> Since I've never seen issues with the camera before I was wondering whether there was anything we could try beyond verifying that the camera connector is in place (as described at http://wiki.laptop.org/go/XO_Troubleshooting_AV#Errors_communicating_with_the_camera)?
>
> Thanks,
> Christoph
>
> --
> Christoph Derndorfer
>
> volunteer, OLPC (Austria) [www.olpc.at]
> editor, OLPC News [www.olpcnews.com]
> contributor, TechnikBasteln [www.technikbasteln.net]
>
> e-mail: [hidden email]
>
> _______________________________________________
> Devel mailing list
> [hidden email]
> http://lists.laptop.org/listinfo/devel

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Re: Cameras not working on XO-1s

John Watlington
In reply to this post by Christoph Derndorfer-2

On Jan 30, 2013, at 3:02 PM, Christoph Derndorfer wrote:

> Hi again,
>
> another issue we encountered during today's workshop session was that on 3~4 XO-1s the camera didn't work (all machines are running 12.1.0 with the associated firmware).
>
> The effect in Record is always the same: a grey still image. However when running the hardware self-test 2 of the machines passed the test even though the camera output on the display was total noise. With the other machine or two the self-test failed.
>
> Since I've never seen issues with the camera before I was wondering whether there was anything we could try beyond verifying that the camera connector is in place (as described at http://wiki.laptop.org/go/XO_Troubleshooting_AV#Errors_communicating_with_the_camera)?
>
> Thanks,
> Christoph

Oh, dear.   You might have run into a failure of the camera flat cable.   We changed the mainframe
in 2010 (IIRC) to fix this, and there is a simple preventative measure to prevent it from happening
on older machines (adding two pieces of cellulose tape to the right place on the motherboard.)
Details and the fix are at http://dev.laptop.org/ticket/10148

As someone already pointed out, please try replacing the camera assembly --- it is the quick
way to see if this is the camera or the motherboard.

Regards,
wad

 



> --
> Christoph Derndorfer
>
> volunteer, OLPC (Austria) [www.olpc.at]
> editor, OLPC News [www.olpcnews.com]
> contributor, TechnikBasteln [www.technikbasteln.net]
>
> e-mail: [hidden email]
>
> _______________________________________________
> Devel mailing list
> [hidden email]
> http://lists.laptop.org/listinfo/devel

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Re: Cameras not working on XO-1s

Christoph Derndorfer-2
James, Gary, Wad,

thanks a lot for all your input and the information.

We now checked all the XOs which showed these camera problems and all the connections seem to have been fine. So I assume that what we're seeing is really the cable failure which Wad mentioned. Unfortunately my Internet connection here at the library is so sporadic right now that I can't download the PDF attached to #10148 but I'll try it again later today. Not sure whether I have the time to still add tape to all the camera modules tomorrow but I'll see what I can do.

Cheers,
Christoph



On Thu, Jan 31, 2013 at 3:39 AM, John Watlington <[hidden email]> wrote:

On Jan 30, 2013, at 3:02 PM, Christoph Derndorfer wrote:

> Hi again,
>
> another issue we encountered during today's workshop session was that on 3~4 XO-1s the camera didn't work (all machines are running 12.1.0 with the associated firmware).
>
> The effect in Record is always the same: a grey still image. However when running the hardware self-test 2 of the machines passed the test even though the camera output on the display was total noise. With the other machine or two the self-test failed.
>
> Since I've never seen issues with the camera before I was wondering whether there was anything we could try beyond verifying that the camera connector is in place (as described at http://wiki.laptop.org/go/XO_Troubleshooting_AV#Errors_communicating_with_the_camera)?
>
> Thanks,
> Christoph

Oh, dear.   You might have run into a failure of the camera flat cable.   We changed the mainframe
in 2010 (IIRC) to fix this, and there is a simple preventative measure to prevent it from happening
on older machines (adding two pieces of cellulose tape to the right place on the motherboard.)
Details and the fix are at http://dev.laptop.org/ticket/10148

As someone already pointed out, please try replacing the camera assembly --- it is the quick
way to see if this is the camera or the motherboard.

Regards,
wad





> --
> Christoph Derndorfer
>
> volunteer, OLPC (Austria) [www.olpc.at]
> editor, OLPC News [www.olpcnews.com]
> contributor, TechnikBasteln [www.technikbasteln.net]
>
> e-mail: [hidden email]
>
> _______________________________________________
> Devel mailing list
> [hidden email]
> http://lists.laptop.org/listinfo/devel




--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]



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Re: Cameras not working on XO-1s

Christoph Derndorfer-2
Hi again,

this may sound like a stupid question but how would one go about swapping out the camera modules?

I couldn't find any instructions on the wiki on how to actually remove the motherboard from the chassis (probably one of the few things I have never done on an XO so far). That step seems necessary in order to access the module because from the front the white plastic piece makes it barely possible to see the cable and push the connector in place with a small screwdriver.

Cheers,
Christoph
 
On Thu, Jan 31, 2013 at 11:21 AM, Christoph Derndorfer <[hidden email]> wrote:
James, Gary, Wad,

thanks a lot for all your input and the information.

We now checked all the XOs which showed these camera problems and all the connections seem to have been fine. So I assume that what we're seeing is really the cable failure which Wad mentioned. Unfortunately my Internet connection here at the library is so sporadic right now that I can't download the PDF attached to #10148 but I'll try it again later today. Not sure whether I have the time to still add tape to all the camera modules tomorrow but I'll see what I can do.

Cheers,
Christoph



On Thu, Jan 31, 2013 at 3:39 AM, John Watlington <[hidden email]> wrote:

On Jan 30, 2013, at 3:02 PM, Christoph Derndorfer wrote:

> Hi again,
>
> another issue we encountered during today's workshop session was that on 3~4 XO-1s the camera didn't work (all machines are running 12.1.0 with the associated firmware).
>
> The effect in Record is always the same: a grey still image. However when running the hardware self-test 2 of the machines passed the test even though the camera output on the display was total noise. With the other machine or two the self-test failed.
>
> Since I've never seen issues with the camera before I was wondering whether there was anything we could try beyond verifying that the camera connector is in place (as described at http://wiki.laptop.org/go/XO_Troubleshooting_AV#Errors_communicating_with_the_camera)?
>
> Thanks,
> Christoph

Oh, dear.   You might have run into a failure of the camera flat cable.   We changed the mainframe
in 2010 (IIRC) to fix this, and there is a simple preventative measure to prevent it from happening
on older machines (adding two pieces of cellulose tape to the right place on the motherboard.)
Details and the fix are at http://dev.laptop.org/ticket/10148

As someone already pointed out, please try replacing the camera assembly --- it is the quick
way to see if this is the camera or the motherboard.

Regards,
wad





> --
> Christoph Derndorfer
>
> volunteer, OLPC (Austria) [www.olpc.at]
> editor, OLPC News [www.olpcnews.com]
> contributor, TechnikBasteln [www.technikbasteln.net]
>
> e-mail: [hidden email]
>
> _______________________________________________
> Devel mailing list
> [hidden email]
> http://lists.laptop.org/listinfo/devel




--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]





--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]





--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]



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Re: Cameras not working on XO-1s

John Watlington

On Jan 31, 2013, at 11:10 AM, Christoph Derndorfer wrote:

> Hi again,
>
> this may sound like a stupid question but how would one go about swapping out the camera modules?

> I couldn't find any instructions on the wiki on how to actually remove the motherboard from the chassis (probably one of the few things I have never done on an XO so far).

Access the motherboard by removing the back (removing the LCD and the microphone cable from the
motherboard in the process of removing the back.)
Remove the speaker cables, the keyboard cable, and the battery cables.
Disconnect the antenna cables to the WLAN module.
XO-1.5 and later: remove the WLAN module
There are three screws holding the heat spreader down (1.5 and later have 4 screws).  Remove them.
You should now be able to lift the motherboard out, starting with the side with two USB ports.

Remove the camera and camera mount as one unit.
Be careful not to damage the motherboard when removing the camera mount.   It is adhered to the
USB connector with double sided tape.    Remove the camera and its mount first,
then disconnect the cable.  When mounting, make the electrical connection before placing the camera
and mount into position.

When reinserting the motherboard, make sure all cables are clear and insert the side with the
audio/power jacks first.

> That step seems necessary in order to access the module because from the front the white plastic piece makes it barely possible to see the cable and push the connector in place with a small screwdriver.

It is impossible to replace the camera without removing the motherboard.   One of the most annoying
simple mistakes I make is mounting a motherboard and starting system testing before realizing that the MB
didn't have a camera mounted...

Cheers,
wad

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Re: Cameras not working on XO-1s

Christoph Derndorfer-2
On Thu, Jan 31, 2013 at 6:46 PM, John Watlington <[hidden email]> wrote:

On Jan 31, 2013, at 11:10 AM, Christoph Derndorfer wrote:

> Hi again,
>
> this may sound like a stupid question but how would one go about swapping out the camera modules?

> I couldn't find any instructions on the wiki on how to actually remove the motherboard from the chassis (probably one of the few things I have never done on an XO so far).

Access the motherboard by removing the back (removing the LCD and the microphone cable from the
motherboard in the process of removing the back.)
Remove the speaker cables, the keyboard cable, and the battery cables.
Disconnect the antenna cables to the WLAN module.
XO-1.5 and later: remove the WLAN module
There are three screws holding the heat spreader down (1.5 and later have 4 screws).  Remove them.
You should now be able to lift the motherboard out, starting with the side with two USB ports.

Remove the camera and camera mount as one unit.
Be careful not to damage the motherboard when removing the camera mount.   It is adhered to the
USB connector with double sided tape.    Remove the camera and its mount first,
then disconnect the cable.  When mounting, make the electrical connection before placing the camera
and mount into position.

When reinserting the motherboard, make sure all cables are clear and insert the side with the
audio/power jacks first.

Excellent, thanks a lot for the step-by-step instructions. If I arrive early enough tomorrow morning I'll give this a shot.

Oh, and I've taken the liberty to copy-paste your instructions to http://wiki.laptop.org/go/Disassembly_top. While the section doesn't quite fit the rest of the page due to the missing photos I think that's the best place to put them so others can find the information in the future.
 
> That step seems necessary in order to access the module because from the front the white plastic piece makes it barely possible to see the cable and push the connector in place with a small screwdriver.

It is impossible to replace the camera without removing the motherboard.   One of the most annoying
simple mistakes I make is mounting a motherboard and starting system testing before realizing that the MB
didn't have a camera mounted..

Hehe, just like one of the workshop participants here on Monday who proudly announced that he had reassembled the whole laptop again - only to realize that he forgot to include the back-cover and therefore had to take the whole upper half apart again. ;-)

Cheers, 
Christoph

--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]



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Re: Cameras not working on XO-1s

Martin Langhoff
In reply to this post by John Watlington
On Wed, Jan 30, 2013 at 8:39 PM, John Watlington <[hidden email]> wrote:
> in 2010 (IIRC) to fix this, and there is a simple preventative measure to prevent it from happening
> on older machines (adding two pieces of cellulose tape to the right place on the motherboard.)
> Details and the fix are at http://dev.laptop.org/ticket/10148

That trac entry has the details of the fix, which involves changing
the main frame of the unit, but Christoph needs the preventative
workaround, which I don't think is described there.

The workaround is to put 0.5mm cellulose tape to act as spacer so that
the camera cable does not get folded so harshly. My rule of thumb is
as follows: when you look at the mainframe on the side where the
motherboard goes, you see an circular extrusion right on the other
side of the speaker would go.

Place the spacer in the middle of that circle. Does not need to be
large in terms of surface.

Put the motherboard + camera assy into place -- when you are in that
process, observe where the camera cable meets the mainframe and check
visually that the spacer is low enough that it will not "pinch" the
cable.

hth,




m
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Re: Cameras not working on XO-1s

Christoph Derndorfer-2
On Thu, Jan 31, 2013 at 9:39 PM, Martin Langhoff <[hidden email]> wrote:
On Wed, Jan 30, 2013 at 8:39 PM, John Watlington <[hidden email]> wrote:
> in 2010 (IIRC) to fix this, and there is a simple preventative measure to prevent it from happening
> on older machines (adding two pieces of cellulose tape to the right place on the motherboard.)
> Details and the fix are at http://dev.laptop.org/ticket/10148

That trac entry has the details of the fix, which involves changing
the main frame of the unit, but Christoph needs the preventative
workaround, which I don't think is described there.

The workaround is to put 0.5mm cellulose tape to act as spacer so that
the camera cable does not get folded so harshly. My rule of thumb is
as follows: when you look at the mainframe on the side where the
motherboard goes, you see an circular extrusion right on the other
side of the speaker would go.

Place the spacer in the middle of that circle. Does not need to be
large in terms of surface.

Put the motherboard + camera assy into place -- when you are in that
process, observe where the camera cable meets the mainframe and check
visually that the spacer is low enough that it will not "pinch" the
cable.

hth,

Hey Martin,

thanks a lot for these instructions. Based on Plan Ceibal's error description I had extrapolated a similar approach and so it's good to hear that I wasn't totally off.

Unfortunately I'm afraid that we simply won't have time to go through the 18 or so XO-1s which currently don't exhibit the problem during tomorrow's session. I will however pass along your instructions to some of the local tech-wizards and maybe they can do the workaround at some point in the near future.

Thanks again,
Christoph

--
Christoph Derndorfer

volunteer, OLPC (Austria) [www.olpc.at]
editor, OLPC News [www.olpcnews.com]
contributor, TechnikBasteln [www.technikbasteln.net]



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