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Start up problem

Former Member

Just started - or trying to - with RPi B version.  Followed up the getting started and connected an HDMI cable to a TV (tested AOK from a working HDMI source), New USB keyboard - tested on another PC and is AoK, and a suitable micro USB mains power source - in one case a Sony EP800 +5V 850mA charger and a Kindle charger of the same rated capacity (this one is on the OK list.).  No video.  Red LED for power but NO Green LED status LED.  +4.94V DC across TP1 and TP2.

 

8GB SDHC ScanDisk card in the card slot ready for formatting.  Doesn't alter the conditions whether card in place or not.  Is my RPi faulty or am I missing something?

  • Adrian Wilkins wrote:

     

    8GB SDHC ScanDisk card in the card slot ready for formatting.  Doesn't alter the conditions whether card in place or not.  Is my RPi faulty or am I missing something?

    I'm not sure what you mean by the SD card being "ready for formatting".  You must copy the operating system to the SD card using a PC before RasPi is able to do anything with it.  For instructions, see:

     

    http://www.raspberrypi.org/quick-start-guide

     

    http://www.raspberrypi.org/downloads

     

    http://elinux.org/RPi_Download_Mirrors

     

    http://elinux.org/RPi_Easy_SD_Card_Setup

  • Adrian, a classical PC has two or three places where they have a megabyte or more of storage for "firmware" that allows the computer to initialize the screen and start booting from the harddrive. Although a megabyte doesn't cost much nowadays, it is the fact that it requires three extra chips that makes this expensive.

     

    So... the raspberry pi has none of these. The raspberry pi processor has just enough "boot code" builtin to be able to load something from the SD card and execute that. This is enough to get the ball rolling. But until you have the code to "initialize the screen" on the SD card you'll see nothing happening on the screen.

     

    If you look closely, the green led next to the bright red power led flashes really short once or twice when you turn on the power. You'll have to put your finger on the red one to be able to see the green one flash. That's how short these flashes are.

  • Thank you for your quick and comprehensive reply.  In the RPi "Getting Started Guide", Page 4, para 1.3 it does state that the RPi requires an SD card preloaded with a version of the Linux OS.  Then it immediately states that you can create your own preloaded card using a suitable SD or SDHC card and on pages 6 to 13 describes very clearly how to do this once a serial connection is established to the RPi.

    I didn't see the green LED flash, so really didn't twig that there was no inbuilt message(s) in the boot code.  I was leaning to the view that you have outlined in your reply but very nice to get it confirmed.  The really useful bit is the link to the RPi_Easy_SD_Card_Setup which nicely solves the problem.  Thank you

  • in reply to Former Member

    Adrian, With a bit of trickery, making an SD card on the rpi itself should be possible. I don't expect wiki-pages to mention that option yet. The thing is: You need  a working raspberry pi for that to get started. So there is a chicken and egg problem....

     

    (And you can mark the thread as "answered", which will probably make John happier, as you'll be awarding him some points for answering your question).