1

In the category "Well, there's your problem": Here it would be if the image would load Somehow the back part of the spring broke off, and the front part got bended. I'm assuming this is the reason for the actual problem.

My PI won't boot any more. PWR is bright-red, ACT is very (and I mean very) dim green. I'm assuming that is because it thinks there's no sd card in there. Could this be right? And if so, what could I do best?

I suck at soldering, don't have the proper tools, and would therefore prefer a software hack over having to solder the two points together. I have considered just dropping some soldering tin on top of the sd-card slot so that it would touch both plates, don't know if that'll work though.

Okay, so with my near infinite skill in soldering and hail-mary attitude I managed to do this: Why don't your images load? However, I still get that very dim green led.

And, as I plug it into my usb-hub, I suddenly notice that my mouse doesn't react any more, and headset fails. This makes me assume there's a short somewhere. I'm assuming this means it's ready for the bin, so I might as well completely wreck it attempting to fix it.

What could I still do to attempt bringing it back to life? What are points I could check for short-circuits? I've got a multimeter here to measure it through where needed.

Improve this question
7
  • 2
    Could you remove the SD card and add a close-up photo of the SD card holder connection to your post?
    – joan
    Jan 18, 2016 at 16:38
  • Um, as well as the bit of plastic it seems you are missing a bit of metal (from the rearmost {the fixed} contact) - did you remove it yourself or is it wedged somewhere on the PCB and shorting something out?
    – SlySven
    Jan 19, 2016 at 19:11
  • @SlySven there's no plastic missing, as far as I know. That iron part is hovering way above the rest of the circuit board, you can consider the spring mechanism completely gone and bypassed by that drop of soldering tin
    – Daniël van den Berg
    Jan 19, 2016 at 21:53
  • @joan I added that in the second picture, I did already bypass the spring SD detection mechanism though.
    – Daniël van den Berg
    Jan 19, 2016 at 21:54
  • My concern was whether an absent bit of metal was somewhere else on the PCB causing problems by shorting something out! Comparing your second picture to mine, I reckon the bent up bit is the "springy" moving contact that is (should be) pressed down by an inserted card - as far as I can tell there is another "non-springy" fixed contact that seems to have snapped off - has the bit that is snapped of been accounted for, or is it wedged somewhere it should not be? 8-P
    – SlySven
    Jan 20, 2016 at 8:53

1 Answer 1

Reset to default
2

Here is what it is supposed to look like, 8-) :

A photograph of an intact SD Card socket on an RPi Model B Rev 2.0 showing the connections to the PWB including the two that are extended to form a switch that is closed when a card is inserted

As you surmise, linking those two wires together will return normal operation - to be honest the wiring up of those contacts is about as much use as NOT wiring up the read-only slider detection contacts on the side. The RPi cannot do anything without the SD Card being loaded and, other than detecting an insertion of the card after the RPi is powered up, is of little practical significance - as that is not best practice anyhow. Of course removing the card whilst powered is as safe as switching the RPi off without shutting down first - and we all know where that leads, don't we, Boys and Girls!

If you can find a way of tying those two contact wires together (a bit of 5A fuse wire comes to my mind but that is just because I have some, somewhere) - that would do the trick - but I'd also carefully wrap a bit of PVC or insulation tape around that to prevent the metal bits coming into contact with anything else.

I take it you do not still have the broken off bit of plastic anywhere - presumably it has disappeared into the same void that all ball-point pens escape to? Otherwise it would be feasible to replace it to effect a repair with some hard-plastic adhesive. I'd be reluctant to use a Cyanoacrylate adhesive (e.g. a Super-Glue™ like one) here as, if you subsequently do have to do any soldering, it will reacts with soldering-iron type heat to release nasty, (I thought cyanide but that is not the case) fumes that are not good for you!

Edit: @joan From the circuitous diagrams for the RPi Rev 1.0 - it still seems to be valid for the Rev 2.0 under discussion:

A extract from the published PDF file showing that portion covering the SD Card socket, showing how the card detection switch is wired to the Broadcomm CPU

As you can see the switch IS wired up to the CPU, and it may be used to tell that that it is "Okay, you can read/write things to an SD card now!" Ripping out the metal without doing anything else, would seem unwise to me.

Improve this answer
3
  • The Pi makes no use of the card inserted signal. It is not connected on the Pi. If that's all that's broken just remove the piece of metal.
    – joan
    Jan 18, 2016 at 20:17
  • Sorry @joan but "The Pi makes no use of the card inserted signal." does not square with the above circuit - IIRC it stops the RPi booting until it sees a card in the slot...
    – SlySven
    Jan 1, 2017 at 20:19
  • Why not get somebody to replace the card holder (socket).
    – Gil
    Dec 9, 2022 at 2:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.