screen does not come on

Discuss peripherals for the XO and power management.

[olpc-help] screen does not come on

Postby Richard A. Smith » Sat Jan 05, 2008 4:42 pm

matt91 wrote:

PS Any idea if Brightstar will be repairing our XOs (with the
aforementioned serial cable) or if we'll just be getting a new one?

Its hard to say right now. Unless you can do repairs in mass with cheap
labor the cost of the labor makes the economics such that its better
just to ship out a new one.

Those DOA units would then get re-purposed for spare parts or funneled
into the developer program where people who already have the skill and
equipment can fix them and then use them.

--
Richard Smith <richard@laptop.org>
One Laptop Per Child
_______________________________________________
community-support mailing list
community-support@lists.laptop.org
http://lists.laptop.org/listinfo/community-support
Richard A. Smith
 

Thanks Richard

Postby Guest » Sat Jan 05, 2008 7:03 pm

Richard,

I appreciate your post explaining, in detail, what the problem appears to have been with our DOA laptops. My laptop was returned last week and I'm eagerly waiting for its replacement.
Guest
 

Question about 3.3V serial debug console

Postby JSL » Tue Jan 08, 2008 9:31 am

I've got a DOA laptop and have been having trouble getting an RMA. Assuming that my battery got dislodged in shipment, I'm perfectly capable of opening the laptop, connecting a serial data cable, and setting the time. Here's the information that I would need:

1) Location of the serial debug port connector.
2) ICD for the port (pins, voltages, data polarity, etc.)
3) Low level & high level protocols for the port (baud, start/stop bits, parity), (HDLC?, PPP?, interactive console?, help screens?)
4) The command sequence required to set the date.

This laptop was intended for my son (who just turned eight). I did not expect to have to open it or troubleshoot it but It's been two weeks since my initial call to the service center (I tried again last Friday too) and I still don't have an RMA. I gave this laptop to my son as a Christmas gift and he's pretty disappointed. I'm willing to do anything I can to expedite the repair.

Jeff
JSL
 

Postby Sambone » Tue Jan 08, 2008 12:57 pm

JSL,

I'm experiencing a similar issue after having found a loose screw, see ( http://olpc.osuosl.org/forum/viewtopic.php?p=8564#8564 ).

I would just like to get it running too and am looking for the same details.

Anybody in the Bay Area that has a serial connector and can help me out?
Sambone
 
Posts: 4
Joined: Mon Jan 07, 2008 1:47 am

Re: Question about 3.3V serial debug console

Postby matt91 » Tue Jan 08, 2008 1:25 pm

JSL wrote:1) Location of the serial debug port connector.


All I can say is that there appeared to be exactly one connector on the MB that was unoccupied. I can only assume that this is the serial connector.

Is there a schematic or other technical manual someplace on the wiki?

Image
matt91
 
Posts: 52
Joined: Thu Dec 20, 2007 1:40 pm

Dead Screen

Postby Sambone » Tue Jan 08, 2008 5:31 pm

I don't think that's it.

The Serial connector is identified on this page http://wiki.laptop.org/go/SPI_FLASH_Recovery

It's location is listed as CN24, On my motherboard I can see the location CN24 (it's near the battery) where the adapter was, now there are just solder pads! So that will mean having to solder to the MB!

Found some more info here: http://wiki.laptop.org/index.php/Notes_ ... per_boards

CN24 Serial port connector to the EC 3.3V levels. (Pin 1: 3.3V Power, 2: TxD, 3: RxD, 4: Gnd, 5: KEY_OUT_3/ISP_CLK)

So now we have the pinouts

Here's a reference for making a null modem cable http://www.lammertbies.nl/comm/info/RS- ... modem.html

Time to look in my junk box to see if I've got any old cables around...
Last edited by Sambone on Tue Jan 08, 2008 5:54 pm, edited 1 time in total.
Sambone
 
Posts: 4
Joined: Mon Jan 07, 2008 1:47 am

Postby matt91 » Tue Jan 08, 2008 5:52 pm

Sambone wrote:I don't think that's it.


Sure enough.

From the link that Sambone provided:
The recovery connector is CN20 on the A-test board. It can be found near the EC. It is a five-pin connector. (Do not confuse with J1 which is a four-pin connector to the north).


The connector in my photo is the J1 (and now that I know what to look for, I do see it on the image).

I wonder if CN20 is under the heat sink, and that's why I didn't initially see it.

edit: It's CN24 on our machines, I guess (vice CN20 as I mentioned)
matt91
 
Posts: 52
Joined: Thu Dec 20, 2007 1:40 pm

Re: [olpc-help] screen does not come on

Postby Guest » Sun Jan 13, 2008 3:37 pm

Richard A. Smith wrote:matt91 wrote:

[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]



Richard: Thank you for a very detailed description of the "no screen" problem!

Living in Norway, I obtained my OLPC through a friend in the US. Unfortunately I have the "no screen" problem and RMA from Norway really doesn't seem like an option for me... both cost and time wise.

Did I understand it correctly that I can:

1. open up the OLPC and make sure the clock battery is in place (and if necessary use some glue)

2. Plug it in, press on button

3. Leave it for a month until the month value changes from 0 to 1. At this point - will the boot sequence continue? Or should the OLPC be turned off and then on again?

Or - is it so that the internal clock starts ticking once the battery is in place again? In that case, I can't see why the computer has to be left on for a month. Shouldn't it be enough to just leave if off for a month until the month value changes and then power it up?

Best regards,

Martin
Guest
 

[olpc-help] screen does not come on

Postby Richard A. Smith » Mon Jan 14, 2008 4:48 am

Anonymous wrote:

Or - is it so that the internal clock starts ticking once the
battery is in place again? In that case, I can't see why the computer
has to be left on for a month. Shouldn't it be enough to just leave
if off for a month until the month value changes and then power it
up?

This is correct. Once the battery is installed the RTC will start
ticking. Note that the wait 31+ days is just a guess on my part. It
_should_ work but this has not been tested. I'll ask my AMD guy if he
agrees with me.

I think your best bet is to send a request to developer@laptop.org
asking if there are any developers near your area that have a serial
adapter and would be interested in helping you recover the XO.

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

_______________________________________________
community-support mailing list
community-support@lists.laptop.org
http://lists.laptop.org/listinfo/community-support
Richard A. Smith
 

[olpc-help] screen does not come on

Postby Richard A. Smith » Mon Jan 14, 2008 5:31 am

Anonymous wrote:

I've got a DOA laptop and have been having trouble getting an RMA.
Assuming that my battery got dislodged in shipment, I'm perfectly
capable of opening the laptop, connecting a serial data cable, and
setting the time. Here's the information that I would need:

1) Location of the serial debug port connector. 2) ICD for the port
(pins, voltages, data polarity, etc.) 3) Low level & high level
protocols for the port (baud, start/stop bits, parity), (HDLC?, PPP?,
interactive console?, help screens?) 4) The command sequence required
to set the date.

This laptop was intended for my son (who just turned eight). I did
not expect to have to open it or troubleshoot it but It's been two
weeks since my initial call to the service center (I tried again last
Friday too) and I still don't have an RMA. I gave this laptop to my
son as a Christmas gift and he's pretty disappointed. I'm willing to
do anything I can to expedite the repair.

Unfortunately, Its not quite so easy. The connector on the board is not
something you can just go and find. Compatible housing and pins can be
purchased from Digikey.

Part# WM1722-ND is the 4-pin housing.
WM2023-ND are the pins.

To use the above you either need to be careful with a set of pliers or
purchase a $200-500 crimper. Most of the serial cables we have at olpc
go from this connector to a .100" female which pops on to the 3.3V
ttl<->USB or 3.3V ttl<->RS232 adapters we have.

Compatible adapter(s) can be found here:

http://www.mouser.com/catalog/632/37.pdf

There are a couple of them that are 3.3V and terminate in bare wires or
in a .100" female header.

The pinout on the laptop is described here:

http://wiki.laptop.org/go/Serial_adapters

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

_______________________________________________
community-support mailing list
community-support@lists.laptop.org
http://lists.laptop.org/listinfo/community-support
Richard A. Smith
 

Re: [olpc-help] screen does not come on

Postby Guest » Wed Jan 16, 2008 5:38 pm

Richard A. Smith wrote:Anonymous wrote:

This is correct. Once the battery is installed the RTC will start
ticking. Note that the wait 31+ days is just a guess on my part. It
_should_ work but this has not been tested. I'll ask my AMD guy if he
agrees with me.



I'll give it a try and report back in a months time :wink:

When I opend the OLPC to locate the RTC battery I found that it was sitting angled, half way out of it's seat. As I turned the OLPC around, the friction of the rubberized feet against my desktop made the battery pop out, so I wasn't able to take a picture of what it looked like...

Thanks for all help so far!

Martin
Guest
 

Re: screen does not come on

Postby Nick Tindall » Mon Feb 04, 2008 12:06 am

Hey Richard, thank you very much for those clear and unequivocal instructions (Sat Jan 05, 2008 11:09 UTC) for upgrading the firmware: very reassuring to us nervous first-time fw upgraders (and potential brick-makers!).

I find the comprehensive procedures on the official wiki, with all their myriad variations, quite daunting. So it's nice to have someone who knows what they're doing say, "just follow these simple steps and everything will be OK." :-P
Nick Tindall
 
Posts: 3
Joined: Thu Jan 24, 2008 5:39 pm
Location: San Martin, CA

Re: screen [...] (De-bricking success)

Postby garydion » Thu Feb 07, 2008 12:25 pm

This post is geared toward anyone who has a bricked, or dead, OLPC which is out of warranty and who is not afraid to tear into it... It serves to encourage others by describing the process to fix the real time clock battery issue under the original G1G1 firmware. You will need a $10 serial adapter and either a soldering iron with a very small tip or an appropriate connector for J1 (more on that below.)

Last night, I received my laptop from an ebay seller and found it to behave exactly like Richard described. The battery and power LEDs blinked appropriately, but the screen sadly never lit up. The seller said the machine worked perfectly prior to shipment, and by all appearances it was brand new. I had no reason to doubt his claim. Soon afterwards, a web search landed me in this forum discussion, and on a few other pages describing the symptoms and possible solutions.

I found the OLPC a dream to disassemble. Four screws and a couple slides later, and the front cover was off. Removing the four screws on the LCD and then lifting it allowed me access to the screws holding on the rear cover (they are marked with triangles.) There is no reason to disconnect the electrical ribbons going to the LCD; simply slide the LCD carefully just enough to expose the four screws. Then put the LCD back and replace one of the bottom screws to hold it there for now. Upon removal of the back cover, you may find the RTC battery falls out of its holder like I did. This is a good sign, since it means this fix will likely work! I put it back in an used a couple dabs of hot-glue to prevent future problems. The machine still would not boot, as expected.

I found this page http://wiki.laptop.org/go/Fix_Clock describing how the real time clock could be set using a special serial adapter. The serial adapters referenced in the article are found described here: http://wiki.laptop.org/go/Serial_adapters and there is actually nothing really special to them. The only real challenge is interfacing to the serial connector on the OLPC motherboard.

This picture shows two connectors on the motherboard: http://wiki.laptop.org/go/Image:BtestRecovery.jpg
But ignore the "recovery connector" outlined in the photo. I actually tried talking to that one first, and while you can communicate with it, it's not the one I used to reset the clock. I instead used J1, the 4-pin white connector to the right of the "EtronTech" chip. What this means is you don't need to remove the large metal plate covering the center of the card. The pinout for J1 is on the serial adapter page http://wiki.laptop.org/go/Serial_adapters about halfway down. It is always smart to VERIFY with a multimeter before you hook up wires that Pin 1 is indeed at 3.3v with the laptop power on, and you measure little to no resistance between pin 4 and ground.

Turn the power back off and remove the battery for this next step...

As I mentioned above, the challenge is to find a connector that fits J1. I didn't have one. Instead, I soldered very fine wires (wire-wrap wire, to be exact) to the BACK of the connector. This way, if I ever wanted to use the right connector, I wouldn't have problems with residual solder on the pins. I then ran these wires to a board I had from another project: http://www.kronosrobotics.com/xcart/pro ... 261&page=1

The board performs the same function as the original OLPC developer serial adapter. It converts and inverts the 3.3v serial signal on J1 to RS-232 on the serial connector. The chip is rated for 5v, but runs just as well on 3.3v for our purposes. There are USB converters available that do the same thing, so just look on the web and you should find one easily. They'll be more than $10, though. For instance: http://www.sparkfun.com/commerce/produc ... ts_id=8165

Finally, I hooked the board to another computer and set my terminal to 115,200 baud, 8N1. On booting the laptop, I saw "Fort" displayed on my computer, followed a few seconds later with more debug information. Following the exact procedure found at the bottom of this page: http://wiki.laptop.org/go/Fix_Clock I was able to correctly set the time in the RTC.

On the following boot, then laptop then came back to life. Trust in knowing the very first order of business was to update the firmware. Yay for being geeky! :lol:

Now to request my developer key to see what other trouble I can get in.

Questions? I'll do what I can to help with answers, but remember I'm standing on the shoulders of all those who wrote the pages I referenced above. A big thanks to them and the whole OLPC team.

-Gary
garydion
 
Posts: 2
Joined: Thu Feb 07, 2008 8:57 am

Re: screen does not come on

Postby matt91 » Mon Feb 11, 2008 12:07 pm

Gary-
Outstanding!

I RMAd my bricked unit, but would have been more than happy to try to set the clock if your notes had been available in December.

There are some threads over in OLPCnews.com about people continuing to get bricked units. I'll post a link to this thread over there...perhaps some of them are adventurous!

Thanks
Matt
matt91
 
Posts: 52
Joined: Thu Dec 20, 2007 1:40 pm

Re: [olpc-help] screen does not come on

Postby Guest » Tue Feb 26, 2008 7:17 am

Guest wrote:
Richard A. Smith wrote:Anonymous wrote:

This is correct. Once the battery is installed the RTC will start
ticking. Note that the wait 31+ days is just a guess on my part. It
_should_ work but this has not been tested. I'll ask my AMD guy if he
agrees with me.



I'll give it a try and report back in a months time :wink:



I tried to turn on my OLPC the other day (>31 days since the RTC battery was replaced), but alas - the screen is still black...

Martin
Guest
 

PreviousNext

Return to Hardware

Who is online

Users browsing this forum: No registered users and 3 guests