Pi DOA

[DrPinball]

Hi

I received my Pi today, but I think it's Dead on Arrival.

I managed to russell up a 2Gb SD card (not SDHC or 4Gb, does this matter?), keyboard, mouse and a HDMI cable.

I tried using Win32DiskImager but it wouldn't see the SD card - nothing in the drives list.

So, I used the alternative from the wiki 'flashnul' which seemed to get the Debian distro on the card.

I plugged it all together and powered up using my HTC 1A phone supply.

I get the PWR light on, but not much else. The OK light is extremely faint but nothing comes up on the screen - yes, I've changed to the correct AV input.

Tried a different TV with a composite cable, but nothing.

Any ideas, or is it back to Farnell for a replacement?

Cheers.

[ukscone]

have you tried booting without the keyboard & mouse plugged in?

[DrPinball]

ukscone said:


have you tried booting without the keyboard & mouse plugged in?


Yep, still the same

[jamesh]

If you plug the SD card in to your windows box, can you see the root partition in explorer? Should be about 80MB with some files with .elf extensions plus others.

[DrPinball]

Can't see anything - Windows wants to format it. I'm trying to copy the debian image again again using the kids' computer, will report back shortly.

Thanks for your assistance.

[DrPinball]

Working now, thanks for the help. Image didn't write with flashnul, worked okay with win32diskimager on a different PC.

Thanks again.

[jamesh]

Good, glad that's sorted.

[grumpyoldgit]

It is interesting that a number of Pi owners have thought that their Pi might be DOA. With a PC there are all sorts of messages coming up on the screen. Even if you remove keyboard mouse, memory chips and hard disk you will get some sort of visual or audio message that can then be used for diagnostic purposes. It seems that on the Pi the error tracking is a little more obscure.

Is there a minimum state that can identify that a Pi is working, even if the SD card is trashed/unformatted or a faulty HDMI cable is being used?

[mahjongg]

It seems the only identification is that the PI tries to read the SD-card, indicated by the blinking OK LED. The PI only has a very tiny ROM (used by the GPU) to load a file from the SD-card, if the file doesn't exist nothing else happens.

[grumpyoldgit]

mahjongg said:


It seems the only identification is that the PI tries to read the SD-card, indicated by the blinking OK LED. The PI only has a very tiny ROM (used by the GPU) to load a file from the SD-card, if the file doesn't exist nothing else happens.



That's still a good diagnostic though. It shows that the Pi is not dead and also what it is trying to do.

[le4thab]

on a side note:- would it be possibel to edit this rom to point to the usb to boot from?

[dom]

le4thab said:


on a side note:- would it be possibel to edit this rom to point to the usb to boot from?



I'm afraid the rom is (unsurprisingly) read only - it can't be edited.

There will always need to be an sdcard inserted to boot.

The sdcard can be very small (8 or 16MB should be sufficient) with the rootfs on USB.

[le4thab]

how would you then point the pi to look to the usb as the boot drive?

[dom]

The cmdline.txt will have something like root=/dev/mmcblk0p2

You'd want to replace that with something like root=/dev/sda1 (assuming that is how your USB disk shows up)

You'll need latest kernel from github that has some USB modules built in.

pepedog runs off a USB disk so may be able to clarify this.

[pepedog]

Exactly, Dom.

Arch has had the modules in for a while because I have rootfs on hard drive since January

[le4thab]

any noob instructions?

[le4thab]

pepedog which is the upgraded kernel?