Fix Clock Using PC as Communication Terminal

 

Summary

 

Is it a RTC clock problem ?

Set up PC as Terminal

Remove the back  panel

Charge the RTC clock battery

Connect  “bricked”  XO to PC  using Hyperterminal  accessory in Windows

Set the RTC clock

Update software

 

Step by Step

 

Is it a RTC clock problem ?

 

  1. Check the symptoms to determine if the malfunction is the RTC problem.  The characteristic symptom is that the microphone LED flashes once, very briefly, immediately after the XO-1 is turned on and the display does not come on..  If the microphone LED stays on, there is a more serious malfunction.

 

Set up PC as Terminal

 

  1. Download, unzip,  and install drivers from http://ftdichip.com  .  Connect FTDI  USB to serial (3 volt) adapter to PC and follow the “new hardware” Wizard that starts up.  See separate instructions for installing the drivers and setting up Hyperterminal.    

 

Remove the back  panel

 

  1. Read wiki topic  Fix Clock . 
  2. Disconnect any power and remove the main battery.
  3. Remove back of  “bricked” XO by partial disassembly. 
  4. View Anna’s Video on disassembly to remove display as a guide (olpcnews forum topic http://www.olpcnews.com/forum/index.php?topic=4773.msg31832#msg31832   .  STOP before disconnecting the display. 
  5. The four screws holding the back are about 1 ½ inch in from each corner.  The screws can be accessed by moving the display down slightly or pivoting it by lifting the bottom edge.   Do not disconnect display (i.e., not necessary). 
  6. After removing the back, replace one of the display retaining screws to keep the display in place.
  7. Assure the RTC “watch” type rechargeable battery is not loose in the computer.  The most likely situation is that the battery is just discharged, although its holder could be out of specification and not firmly hold the battery. Do not attempt to remove RTC battery if it is firmly in its socket.

 

Charge the RTC clock battery

 

  1. With the RTC battery in place, charge it by applying power and powering on the XO for several hours (even though the display does not come on). The RTC battery charges only when the XO is powered on.

 

Connect  “bricked”  XO to PC used as communication terminal

 

  1. Power off and remove power and main battery.
  2. Connect the USB to serial adapter to the internal serial port of the “bricked”. 
  3. Install the main battery. 
  4. Connect the adapter to the PC using the USB to serial adapter cable..
  5. Start the PC and then Hyperterminal in Programs>Accessories>Communications .
  6. Select an existing Hyperterminal setup or start a new one.
  7. Turn the “bricked” XO on.  The firmware commands will be echoed to  Hyperterminal: 

                          +

                           Forthmacs

                              .

                              .

                              .

                            Init SHA-1 variables

                            Page Fault

                            ok

 

Set the RTC clock

 

  1. Use Hyperterminal to enter the commands to set the clock on the “bricked” XO.
  2. Power off the now repaired XO by holding in its power button.
  3.  Shutdown the PC.  Disconnect the USB cable. 
  4. Remove the main battery from the repaired XO. 
  5. Remove the serial cable from the repaired XO.
  6. Reinstall the main battery on the repaired XO.  It should now boot normally, but the keyboard  and mouse will appear to not work.  Shutdown the XO.

 

Update software

 

  1. Update the software to version 10.1.3  using a clean install from a USB drive.  This is done by  placing a USB drive with the software into one of the USB ports and powering ON the XO while holding down all four (4) game keys.  Follow the instructions on the screen.  After the installation is complete, shutdown (power OFF) the XO  and remove the AC power and the main battery.  This erases any old parameters stored in the hardware.  Reinstall battery and / or AC power.