So, what's the story?

Hard to say... I have probably bought and used half a dozen or so. Never had a failure on any of them.

Could it be a SD card problem, or PSU related, are you taking ESD precautions when handling them?

--
Cheers, 

John. 

/=================================================================\ 
|          Internode Ltd -  http://www.internode.co.uk            | 
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|        John Rumm - john(at)internode(dot)co(dot)uk              | 
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Has it maybe occurred to you that you might be doing something wrong?

Indeed no-one is expected to accept an 83% failure rate, and I can understand your frustration, but if you don't tell us what failures you're seeing, and what you've tried to investigate, then all we can say is good luck with the chickens.

I can assure you, that despite your prejudices, the pi is far from "crap", and getting all emotive is not going to endear you with the people here.

I have five. One failed when I hooked up the power backwards on the header pins. One failed because we were carrying it around unboxed in a backpack with the SD chip still installed, and leverage eventually cracked the plastic back off the SD socket.

Three work fine. You'd better take a look at what you're doing to yours.

SD chips can be a problem -- the various brands have models that work and models that don't. See .

Power can be a problem. Feeding the RPi its half-an-amp down the 28-gauge conductors in a cheap USB cable might work, or it might not. Adafruit Industries are zeroing in on the problem: but I think many people here will report that they got good results without going to special trouble. A voltage measurement across TP1 and TP2 will show you what you're really feeding.

Mel.

Same SD card, same power supply same handling for all of them. Just sit there and rotate among them all. One worked from the start and still does the others were DOA and after multiple rotations are still dead.

bill

--
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves 
billg999@cs.scranton.edu |  and a sheep voting on what's for dinner. 
University of Scranton   | 
Scranton, Pennsylvania   |         #include

Sigh.... Been doing this for over 30 years. I'm not an idiot.

What part of DOA do you not understand. Insert SD (that works in at least one. I have both Linux and Plan9 SD cards.) Insert HDMI cable. Turn on monitor. Connect power cord. And, nothing. Red LED lights. the Green LED that usually flashes, doesn't. It's not like this is rocket science.

Prejudices? I heard the Pi was a good platform so I ordered some. In the meantime my boss gave me one to try (well, two actually because the first one didn't work). Before the first order arrived I saw the deal from Allied mentioned here and ordered a couple more because if they worked like people were saying I had a number of potential projects I wanted to try. How is that showing prejudice?

83% DOA is crap.

bill

--
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves 
billg999@cs.scranton.edu |  and a sheep voting on what's for dinner. 
University of Scranton   | 
Scranton, Pennsylvania   |         #include

iBut these appear to be failures after you had them working. Mine didn't work right out of the box.

Like I said, it ain't rocket science. Plug in SD card, plug in HDMI cable, plug in power. What cold one do wrong?

My two test SD cards both work just fine in the one functioning Pi. Linux on one and Plan9 on the other. Booted them on the good Pi this morning, just being sure.

Same thing. I have three power suppies, all advertised as Pi power supplies. They all work on the one working Pi. The most recent failures were the ones from Allied. Took them out of the plastic boxes they shipped them in oonto a wooden work surface, plugged in all the attachments and nothing.

I'll try that just for the fun of it but at this point, based on what I am hearing here, I think I need to look for something better than the Pi for my projects.

bill

--
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves 
billg999@cs.scranton.edu |  and a sheep voting on what's for dinner. 
University of Scranton   | 
Scranton, Pennsylvania   |         #include

Are the faulty ones Chinese or UK built? What are the version numbers? Can you trace the distribution route? How were they packed on arrival?

What about the good one?

--
W J G

You may not be an idiot but 30 years has not taught you how to respond to people who are trying to help. At least IMHO Tony's comment was very relevant. Because we don't know how expert you are a query as to what you mean by DOA seems sensible.

My suggestion is to take the two from Allied and get on to them with the problem you have. As they apparently sell new kit you should expect theirs to work from day one. Can't say the same about the ones you got off ebay. Once you have the Allied ones working then you can check the ebay ones again.

As the Pi is normally sold without power supply or storage there can be issues with peripherals that are sold by others. I've seen comments of failures especially with borderline PSUs.

Agreed.

James

1) Destroy the card by static damage.

2) Feed too low a power supply voltage into them because you're using a cable that is too long and/or too thin.

3) Feed too low a power supply voltage into them because you're using a power supply of inadequate current rating.

4) Feed too low a power supply voltage into them because you're using a faulty power supply that no longer supplies its rated current.

The last three are amenable to diagnosis by measurement of the power supply voltage arriving within the card. It ain't rocket science.

Do let us know what you find.

And percentages of 5 units isn't rocket science either, but I see you've come up with a wrong answer. 4 out of 5 is 80%, not 83%.

Dave

Does no one even bother reading what I said? OK, that's rhetorical...

The cards I am using work in the one good Pi. They do not work in the

5 bad ones.

Power supplies I am using were, supposedly, made or at least speced for use with the Pi. In any event, they all work with the known good one and do not make the suspected bad ones work.

see above.

see above.

I said I would test that, but the fact that I have one that works and 5 that do not tends to make me think either the SD cards and power suplies are good or I have one miracle Pi that doesn't seem to require the speced power.

See first comment at beginning of message.

Two from my boss, one that worked and one that didn't. Bought four, none of which worked. 5 out of 6 DOA looks like 83.333333333333333% to my calculator.

bill

--
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves 
billg999@cs.scranton.edu |  and a sheep voting on what's for dinner. 
University of Scranton   | 
Scranton, Pennsylvania   |         #include

I recall reading about some issues with particular memory chips vs particular boot code.

(However this might only apply to RISC OS, not Linux)

You might just have 4 new models and one old model, and a boot image that will only handle old models.

Are you using a recent download?

--
Alan Adams, from Northamptonshire 
alan@adamshome.org.uk 
http://www.nckc.org.uk/

Ok, what have you actually tried to do for troubleshooting other than switching the cards?

What model and revision Pis have you got?

How recent are the OS images that you have tested with?

Does the green ACT/OK do *anything at all* after you connect power? (Glow faintly, flash briefly, flash a few times, stay totally dark)

As for one of your other questions, yes different Pis can be sensitive to differing power levels. All components have tolerances and the F3 polyfuse can vary quite a bit. But it should work with a proper PSU and lead.

Your Pi failure rate is way too high to be believable (although I wouldn't trust the ebay ones). Something else must be wrong.

That is certainly a valid point; the "new" model will not boot from an old image that works fine on an older model. A friend ordered a Pi bundled with pre-loaded Flash card a few months ago and it would not boot. Downloading a new image and writing it on the same card fixed that.

That was my feeling too..but I had insuffient expereince with pis to voice it.some hardware/boot image mismatch..

--
Ineptocracy 

(in-ep-toc?-ra-cy) ? a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers.

On 19 Sep 2013 19:50:35 GMT, snipped-for-privacy@server2.cs.scranton.edu (Bill Gunshannon) declaimed the following:

Okay, maybe you have one unit that is more tolerant of borderline SD cards...

--
	Wulfraed                 Dennis Lee Bieber         AF6VN 
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

There can be manufacturing variation in components.

One possibility: Perhaps something external to the Pis (power supply, SD card, keyboard/mouse current draw, etc.) is just out of spec, and one of the units is tolerant but the other units aren't. For a purely hypothetical example, let's say the power supply is putting out 0.10V less than the minimum specification, the one Pi would work with a supply voltage as low as 0.15V below min. spec, and the other Pis quit working with a supply voltage of 0.05V below min. spec. That would fit the observed symptoms.

If you had at least two, preferably three or more, power supplies and SD cards, and the one unit worked perfectly with all combinations of PSUs and SD cards, but none of the other units would work with any combination of PSU and SD card, that would be much better evidence that the Pis are at fault.

Do you have an accurate voltmeter to check the power supply voltage?

HTH

--
Robert Riches 
spamtrap42@jacob21819.net 
(Yes, that is one of my email addresses.)

First rule of troubleshooting (as you will know) is remove common items.

I would suggest taking all of your PIs to another user and (without prejudicing them) ask them to try setting them up. Just the PIs not any of your other gear, not even the SD cards.

Of the 20 or so PIs I have had brought to me with tales of woe (it's dead / it does nothing / these are crap / etc. etc.) I have had 100% work first time when I set them up.

If they still don't work then return them to seller under the terms of the sale of goods act (or whatever equivalent you have over the pond).

--
nev 
getting the wrong stick end since 1953

Could this be it?

Allan Bennett

I assume you've already been though everything from here:

?

--
(\__/)  M. 
(='.'=) If a man stands in a forest and no woman is around 
(")_(") is he still wrong?