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I have a raspberry pi of model B. This is not reading any SD card. The act LED is not blinking - ( according to raspberry pi documentation) which indicates it is not reading SD card. Now is there any way to boot the pi? Can a USB stick be usable to boot?

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This is not reading any SD card.

It won't read "any SD card". It will only read one which has been properly formatted. Most models with no SD card, or an improperly formatted SD card, will simply show the power light; the 2 (and possibly 3) are an exception in that they will have both red and green lights on steady.

It may be that the green light is actually "glowing faintly" although this could be hard to tell unless you dim the ambient light. That would confirm that it simply has not found a viable card. See here for further details.

Can a USB stick be usable to boot?

No.


Here's a problem I have with a model B I've had for a while that exhibits the exact same symptoms -- but for which there is an easy fix.

enter image description here

Look closely at the left side of both holders. The one on the left is missing part of the plastic that is still present on the (unbroken) holder on the right.

I did not even notice this happen, but I did see the 2 millimeter wide (and 1/2 mm thick) piece of plastic lying on a table where I had been using the pi. Those holders are not very sturdy and, particularly after a few years of sliding cards in and out, it would be easy to break one and never know. Also worth noting is that the case on the right has a layer of thick acrylic all the way across, pressing firmly against the holder, which is probably why it is not also broken.

Adding to the stress on the flimsy holder, and part of the cause of the subsequent problem, is that the metal connectors at the end are springy -- not because there is anything behind them which yields when a card is inserted, but because the metal is suppose to press flat, squeezing the card against the flimsy plastic.

Without that little strip on the left, this pi usually will not boot as is; it behaves exactly as if there is no card there. However, inserting a card feels the same, and it stays in place, and pretty much looks the same as well.

My fix for this was to wedge some pieces of pull tie across the holder, wedged into the case. It is not a very good fix but it is fine for what I use that pi for now (note the hint of velcro at the bottom though :) it has been in a used in a few strange positions before).

It is easy to tell if the holder is broken this way if you have another one to compare it to. I think it could be difficult otherwise -- the contrast and shadow in that image exaggerate the slight roughness I can see with my (20/20) eyes in bright light. And that's only because I squinted at it after finding the same color plastic sliver on the table.

It is also easy to tell if it is the cause of the booting problem by inserting a card you know should work, holding it firmly in place with your thumb directly over the business end where the connectors are, and plugging the pi in. Obviously: Do not let your grip slip at all if you must then turn the pi to look at the green ACT light.

  • "Can a USB stick be usable to boot?" No. Wrong instructables.com/id/Boot-the-Raspberry-Pi-from-USB – Android Dev Apr 22 '16 at 0:23
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    @AndroidDev Wrong. If you look at that photograph, you'll notice the pi has an SD card inserted. IT IS BEING BOOTED FROM THE SD CARD, THEN USING THE USB DRIVE FOR THE ROOT FILESYSTEM. The "IT guy" who wrote that is using the term "boot" in a very loose / colloquial sense to indicate the operating system is on the USB stick. But you still MUST have the bootloader code on an SD card, and that will then use the stick. If you read the comments on that Instructables, you'll notice one or two other people observe the same fact (e.g, the 2nd one, from "DavidR123"). – goldilocks Apr 22 '16 at 0:59
  • See esp. Step 3 of the same Instructables, "Preparing the SD Card"".... – goldilocks Apr 22 '16 at 1:14
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    I stand corrected. I didn't actually read the entire article; just skimmed it. – Android Dev Apr 22 '16 at 1:27
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    It's possible the reader is broken, e.g, a connection at the holder. We get occasional reports of that happening, although far more common are people that thought they has a properly prepared card, tried another method, all of a sudden it works. But if you think it is really busted and you just got it, send it back to the distributor and explain the problem. They will refund or replace it. – goldilocks Apr 22 '16 at 12:11
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Had a similar problem with an old RPi 1B not booting from the SD. Tried all kind of software and configuration fixes. Very occasionally it worked then stopped again.

Then I tried pressing on the SD card while booting and then it boots 100% ok. I cleaned the connections to card and the SD connector on the Pi using a special PCB cleaning brush (fibreglass bristles) - no improvement at all. I resoldered all the connections to the Pi SD connector - no improvement.

I now the RPi in a workshop vice, squeezing the card onto the Pi socket - it boots fine. It gives the impression that the card has the fault rather than the Pi, but since I can write to card from my PC ok, then I guess the card must be OK. I think it's time for my ditch this old RPi!

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