Learning to Repair XOs

Trip Start Oct 14, 2009
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Trip End Jul 01, 2014


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Flag of United States  , Massachusetts
Thursday, March 11, 2010

I spent this afternoon with OLPC Volunteer extraordinaire, Ian D. at his OLPCinci Repair Center office at Olin College, in Needham, MA. I connected with Ian thanks to Donate Your Get One Donor, Kathleen Archer, from CT. Kathleen's G1G1 XO did not boot when turned on. Rather than send it to the VVV project "broken," Kathleen located Ian's OLPCinci Repair Center and sent the XO destined for the VVV to Ian for repair.

Ian agreed to teach me to disassemble the XO, and to perform the repair to "Fix the Clock" problem that often causes early G1G1 XOs to not boot up when powered on. If you have an XO that has been left unused for several months, and the LED power light and battery indicator light up when turned on, but the screen remains black and does not boot, it is likely that the problem can be repaired and afterwards, your XO laptop will be just like new! We fixed a couple of these and I have 2 more to do at home! Hopefully I will be able to help other volunteers who have encountered this problem with the first generation XOs.

The short explanation for the clock problem is that an early vendee, a South American government, planned to buy and lease their XOs. They apparently wanted the XOs to stop working after a prescribed length of time.  This feature was built into the rechargeable Clock battery on the motherboard. To repair this problem, the clock must be reset by attaching a serial adapter between the damaged XO and another computer, either an XO or a conventional desktop or laptop and running a set of commands. The repair requires a special serial adapter.

The repair instructions are on the OLPC Wiki at:
http://wiki.laptop.org/go/Fix_Clock

We also repaired one XO that had no sound when booting. I have written up instructions for this that make sense to me. I will put these in the Wiki when I figure out where they belong.

First I learned to run diagnostics to determine if the problem is software related or hardware related. Open firmware (OFW) has a test to check all of the hardware and if the wifi works
http://wiki.laptop.org/go/Cheat_codes
To run the diagnostics, while pressing the power button, hold down the 'left rocker' key to activate these tests.

XO Sound Settings, Repair Hints and How to Make Headphones Work
1. If the booting up sound does not work, try this:
Turn on the power button. When the black and white XO comes onto the screen, but before the little dots appear, press and hold the Volume Up button on the XO. Then turn off the XO and reboot it.  If the problem is not the speakers, the boot sound will play and you will have fixed the "firmware" issue.

2. If you are not certain whether the speakers work, run the OFW test to check for sound.OFW(open firmware) and the OS(fedora) access the sound hardware in different ways. So if it works from OFW --- producing the chime -- and not from Sugar, then its a software issue with the OS(sugar or fedora) but if no chime plays, then it might be the speakers or some other odd thing (or a muted chime).

3. Beth Santos recommends a shortcut that she says has fixed 100% of her speaker problems: "From the
terminal activity, type

amixer sset PCM 90% unmute

Press enter. All fixed."

4. Check and adjust the Sound and Volume settings by accessing the "Developer Console".

            1. Press Control, Alt and the Group View (the key at the top left with 3 dots), simultaneously.
            2. Hit Enter to log in
            3. after the bash response, type the word
            alsamixer
            4. You will see the volume controls. On this screen you must use the arrow keys to move between the controls. You can adjust the Master Settings and change the defaults here.
            5. The settings with a 00 at the bottom are on, and the settings with MM are muted. You can increase the settings and the volume on the Master, MasterM and PCM by scrolling and highlighting each with the side arrow key, then increasing or decreasing the bar with the up or down arrow key.
            6. You can Mute or Un-Mute using the M letter to activate the toggle feature.

5. How To Enable Headphones to Work on the XO:
To change the XO default so that headphones will work when inserted into the headphone jack, scroll with the right arrow to the 4th column labeled "headphone." Press the M key to change MM to 00.

When you have the desired settings, to exit this screen, press the escape key, the x in the top left corner. Now you will have to turn off the XO by pressing and holding the power button. When you reboot the XO, your new settings will apply.

Insert your headphones into the green headphone jack and open the Tam Tam Mini Activity. You should now be able to hear music notes through your headphones when pressing the keys on the top letter row! Have fun.

If you are using these instructions (I hope so) and want to understand more, Support Gang volunteer James Cameron explains: "so you understand why this Beth 's shortcut, (#3 above) sometimes works:
1. there's more than one actual volume control inside the laptop, and they are "in series", in that if either of them is off, you get no sound,
2. only one of the volume controls is given to the user on the frame,
3. the internal volume controls are saved on shutdown and restored on reboot, they are saved in a special file,
4. some applications or activities may make changes to the internal volume control ...... and if the activity doesn't change it back (e.g. because it crashed, or the laptop was shutdown) then this can lead to a "no sound" problem, that can't be cleared by rebooting. What that amixer command does is to turn up one of the internal volume controls. On next controlled shutdown, it is saved.

I also learned to replace a keyboard and some other things too. Ian has earned the OLPC Volunteer of the Month award for his patience in teaching me! Thank you Kathleen for connecting me with Ian. Dr. Sam Venus, Mayo Clinic, Minnesota, is leaving for Hanoi this week and will be bringing your repaired XO along with him for the VVV project!  Thank you Dr. Sam too, and special thanks to Ian for your generosity and time!





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