[olpc-help] screen does not come on

[Richard A. Smith]

matt91 wrote:

> This is exactly the problem we are experiencing (power light, but
> that's all). And taken together with the fact that I know my battery
> wasn't seated well (see photo above), it appears that I/we were
> bitten by this firmware bug.
> 
> This leads me to another thought...how many other G1G1 units (with
> the 'bad' firmware) have a battery just waiting to pop out and brick
> the units?

I've been preparing my "official" post on this but since you seem to
have all the pieces stuck together I'll just respond in this thread.

I finished a root cause failure analysis on the DOA laptop I received.
The cause is indeed due to the RTC battery coming loose.

On laptops with system firmware <=Q2D06 if the clock gets cleared a
value of zero in the month value causes the firmware to stop early
on in the boot process.  So the laptop boots but never gets to a point
where the user can see any visible activity.

Unfortunately the only way you can recover from this is to disassemble
the XO, attach a serial connection to the serial debug port and set the
clock manually.

[Or You might be able to power up the XO and wait 31 days until the
month value changes from 0 to 1, but I doubt anyone wants to do that]

Attaching a serial port requires you to have a 3.3V TTL to serial
adapter and the special small connector to mate with the connector thats
on the motherboard.

Unless you are a electrically inclined I don't recommend it as the
recovery method.  If you have the "no screen" or DOA problem then I
suggest you RMA the laptop.

The root cause of the battery coming loose is that one of the suppliers
of the battery connector had a factory with a mold that was worn out and
had not been replaced.

Based on all the data we have right now we think that less than 500 XO's
were affected.  Knowing a more exact number is difficult.  We think that
all of the affected XO's went to the G1G1 program.

Laptops with Q2D07 does not have the page fault problem.  We fixed the 
RTC bug by then.  The mold problem was also found an fixed by the
manufacturer fairly quickly.  There is a small window of overlap where
the XO's got Q2D06 firmware _and_ a mix of bad/good connectors.
Those are the laptops that have a chance of turning into a brick if the
battery comes loose.

If you have Q2D07 all that happens is that you lose your date.  Which is
easy to fix.

My recommendation for the community is to first upgrade your system
firmware to Q2D07. (Procedure below)  That will keep you from ending up
as a brick.

Then if you find that you are constantly losing the system date then to
disassemble your laptop re-seat the battery and add a bit of hot glue on
the edge of the connector to keep the battery in place.

The procedure for upgrading your firmware is:

1. Make sure your battery is charged
2. Plug up the XO on external power
3. Open the Terminal activity
4. wget http://dev.laptop.org/pub/firmware/q2d07/bootfw.zip
5. su -
6. cp bootfw.zip /versions/boot/current/boot/
7. reboot

The laptop will then reboot twice more on it own.  Once to enable 
writing to the flash and then a 2nd time after its done updating.

step 4 can also come from a USB key if you don't have networking available

Steps 1 and 2 are NOT optional.  The XO will not upgrade system firmware 
  unless it has a battery and external power.  To do unsafe firmware 
upgrades you have to have developer key. If you lose power during a 
firmware upgrade you will brick the laptop.

Rather than try to find out what firmware you have I would just do the
upgrade and not worry about what version was there previously.  The XO
will only upgrade the system firmware if it finds that the current
version is earlier than whats in bootfw.zip

You can also just wait for Update.1.  Update.1 will have Q2D08
(unreleased as of now) system firmware.

If you wish to verify that you have really upgraded your firmware then 
open up the terminal activity and:

cat /ofw/openprom/model

You should see the string "CL1  Q2D07  Q2D"

Thanks.

-- 
Richard Smith  <richard at laptop.org>
One Laptop Per Child