[olpc-help] screen does not come on

[Richard A. Smith]

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 at laptop.org>
One Laptop Per Child