So, what's the story?

Probably just a typo - they get it right a couple of lines further down: "Without the polyfuse limiting the current".

I have already stated precisely that. Three power supplies, advertised as RaspberryPi power supplies, and two SD cards, one with Linux and one with Plan9.

One Pi works with any combination and the others do not work with any combination.

Yes, but while I may test them out of curiosity, I am inclined to stick with my original thought. Shoddy product, no QA. And I am certainly not inclined to try some more. Fool me once, shame on you; fool me twice, shame on me.

bill

OK, this was the most important information I got so far!!!

It made me pull them out of the cute little boxes I had for them in order to compare them. Board and chip configuration all appear to be the same so I assume they are all the same model. However....

There is one difference, The working one say "Made in the UK" and all of the non-working models say "Made in China". Unless someone knows of something unique to Chinese Pi's that requires them to be dealt with in a different manner, then I rest my case. Chinese crap, as I stated in the first place.

bill

they may be not genuine pis at all.

But still try the later boot images

Its a shot to nothing...

Aha, some information.

The photos I see of Chinese Pis have Samsung DRAM, while many of the earlier versions have Hynix DRAM. If you don't have a recent flash image the Samsung ones won't work. You can see the Samsung DRAM chip to the left of the Pi logo here:

Grab a copy of NOOBS:

Theo

Wait, your saying there are counterfeit RasberryPis? And they are being sold by supposedly legitimate companies like Allied? And they are subject to not working like a "real" raspberryPi?

Now that sounds like a platform I would really want to work with.

I will try, but just out of curiosity. This experience has more than convinced me that the Pi is not something I want to devote any more time to.

And hardly a strong selling point.

bill

I'm not aware of any counterfeit Pi's - I'd have thought that getting the GPU/CPU would be tricky, but who knows...

All the early Pi's were chinese - the best part of a million of them. I have 3 working fine. The current chinese Pi's are red, but the early ones were green.

Rev 2's have 2 big holes in the board. Rev 1's don't.

But it is worthwhile checking the RAM chip though and making sure you have the latest image.

Gordon

You were given several suggestions that would have pointed you to this possibility, but seemed most reluctant to follow them through (such as a more recent boot image). You also seem to be reticent to give us any meaningful information about the boards you have. This makes me wonder if you actually

If you really don't care for them, just pack them away and give them to your local Linux group / IT club. I'm sure they will appreciate the gift - and the challenge.

Feel free to send the bad ones to me. I would be happy to see if I can get them to boot. gnuarm at gmail dot com

thank your lucky stars it wasnt a Sinclair kit..

In comp.sys.raspberry-pi message , Thu, 19 Sep 2013 15:12:24, Bill Gunshannon posted:

At your age, one who writes like you is a poor advertisement for his University. One therefore assumes that you have been approaching your problem in a similar slapdash manner, and advises accordingly.

The first thing to do, as the power supply is of fundamental importance in any electronic equipment, is to check the voltage actually delivered at the Pi itself, using both a small d'Arsonval meter in a reasonable state of calibration and a traditional oscilloscope - those, and if necessary training in their proper use, should be available in Scranton

- and to report the results.

some newer units need a newer OS image on the SD card.

They were no problem. Assemble the kit as per the instructions, find it didn't work, send it back to Sinclair, get a fully working one off the production line back a couple pf weeks later. It's one of the reasons they went out of business.

I was going to reply to this but your not worth it.

I thank the people who actually helped but at this point I think the Pi's will be relegated to a shelf in the basement until they finally end out in a trashcan and I will look for more reasonable devices to use for my embedded projects.

bill

The trashcan is no place for them. I would be happy to have them. Please send them on to me. Email me at gnuarm at gmail dot com for a mailing address.

Remind me, my memory may be failing, but I think the only Sinclair computer sold as a kit (apart from the mk14) was the ZX81, you saved £10. I think they withdrew the option due to excessive botched returns. I don't recall the ZX80, Spectrum or QL marketed as a kit.

On 21/09/2013 14:04, Bill Gunshannon wrote: []

Do, at least, try them with the current OS distribution:

I think you're right. There were however a number of other products sold as kits - various audio stuff, the Black Watch etc. Most used "working reject" components, so even it they worked initially, they tended to fail quite quickly thereafter.

The "scientific calculator" redesigned a Texas Instruments chip, removing the guard bits to create program memory. As a result, the numeric accuracy suffered.

(sin 7 degrees)^2 + (cos 7 degrees)^2 produced, as I recall 0.993 instead of 1.

(The HP model of the same era produced 0.99999997)

I'm afraid your memory has played you falsely. I built a ZX80 kit, saving myself 20 quid on the pre-built price of £99.99 (and getting a "CCT" diagram into the bargain - very useful for designing and building my own 3K srampack a year before Sinclair got off their big fat backside to ship their infamous 16K rampack).