Saving a bricked phone with a pencil lead

[stompyonos] bricked his Samsung Captivate. Not wanting to be without a phone for a while, he researched a fix online and found shorting a pair of pins on the USB port would put the phone into download mode, saving his phone. The only problem for this plan is [stompy] didn’t have any resistors on hand. Instead, he came up with a wonderful MacGyverism using a piece of paper, a bit of graphite, and a pair of paper clips.

The process of unbricking a Captivate requires a 300 or 330 kΩ resistor across pins 4 and 5 of the mini USB port. This can be done with a few resistors, but [stompy] only had a multimeter lying around. After scribbling a good bit of pencil lead on a piece of paper, he attached two paper clips to make a variable resistor, dialed it in to about 300 kΩ, and cut up an old Nokia charger for its USB plug.

Not bad for a very easy fix that didn’t cost [stompyonos] a dime, and certainly better than a $500 paperweight.

Comments

  1. NotImpressed says:

    I just did this same thing to fix a PCB trace.

  2. fartface says:

    Stompy needs to go and buy a pack of resistors. You lose a LOT of street cred by not having resistors around.

  3. sneakypoo says:

    Ah reminds me of the good old days of scribbling with a pencil on the AMD Thunderbird processor to unlock it for overclocking.

  4. cgimark says:

    Another thing you can do if you don’t have the pencil is to use water and salt on a plate, paper.

    Or if you have a potato you can insert probes till you get the right resistance.

    Note: NOT to be done with anything but 5-12VDC low current circuits.

  5. m1ndtr1p says:

    The actual resistor required is 301 kΩ for this to work, some phones are finicky at anything above or below that… I just made a dongle for my old Captivate which is about the size of the micro USB connector and its casing, the resistor is embedded inside.

  6. Sven says:

    While this is shows the innovative properties of the guy in question, the fact that he did not have any resistors on hand kind of cancels it out.

    Unless he did this while visiting somewhere away from his proper lab in which case it’s all great! :P

  7. adcurtin says:

    > short

    it’s not a short if it’s through a resistor.

    > $500 brick

    The Galaxy S 1 (aka captivate) is not worth anywhere near $500. It’s more around $200. The Galaxy S2 isn’t even worth $500, and the GS3 is only just over that mark.

    • kaidenshi says:

      Did you ever consider that the guy might have bought the phone unsubsidized when it was first released? In that case, yes it did cost him nearly $500 and I for one would not want to throw that investment in the trash.

      And yes, I know you can pick up a replacement Captivate off the street for around $100-150 these days but that would put his total investment over $600. I think he did a great job saving himself the headache and cost of replacing the phone.

      For this to be a hardware hacker site, there sure is a lot of hate for homebrew fixes and hacks. “It’s a cheap phone, just buy another one” is pure consumerist bullshit.

      • adcurtin says:

        I am not hating on the hack. It sucks that he doesn’t have resistors, but it’s pretty cool he figured out his issue in a different way.

        However, a short is 0 ohms. it could be phrased “short through a resistor” and that would be ok, but short by itself is incorrect.

        Also, cost and worth are two completely different things. If you brick a phone that’s worth $200, it’s a $200 brick since it can be replaced for that much. It may have cost $500, but it can be replaced for much less than that. The whole point is that $500 brick is overly dramatic.

      • kaidenshi says:

        I never said anything about the “short” comment, in fact I agree with you. I’m not really sure why you brought that up in your reply to me.

        But again, I stand behind what I said regarding the total cost of ownership of the phone. Granted, we don’t know for sure if he got it subsidized or paid full price, but either way the original cost of the phone plus the cost of a replacement is far more than this zero dollar fix. To argue otherwise is to display a level of ignorance I’ve honestly never encountered here before.

    • rather good says:

      I bet you have many friends.

  8. bothersaidpooh says:

    Yet another reason to add a “dial a resistor” box to your luggage :-)

    In fact the other way to homebrew resistors is to use PVA glue and some graphite lock lubricant.
    Memo to self, ask for “lock unsticker”

    Works fine but loses/gains resistance if oven heated.

  9. AdamOutler says:

    Wow. This is a great hack! Awesome job man.

  10. Hirudinea says:

    And for his next trick he’s going to make a router with a rusty razor blade and a safety pin (Foxhole radio.)

  11. Filipe YaBa Polido says:

    Take that kiddies! This is old school :)
    Nice work stompyonos. However, I do have to agree, WTF are you doing without resistors and capacitors in some drawer?! ;)

  12. PocketBrain says:

    I love this sort of hack! I tried using resist ink as a strain gauge (it was too brittle), and I do remember a kid using HB leads as resistors in a science project (do they still do those nowadays?) back in 1980, in an audio amp. The

  13. Philippe says:

    Nice job!

    I once needed a countdown stopwatch that I could use in a classroom.
    I found one, sort of a kitchen timer, that had the big display and the functions I needed. Unfortunately it also came with an annoying buzzer that would beep when the countdown reached zero.
    I opened the case, found the piezo disk and placed a piece of paper to isolate its contact from the main board.
    Alas, the stopwatch stopped functioning altogether: as it turned out, the piezo element was part of the circuit.
    By a (very rare) stroke of genius, I had the idea to scribble on the paper with a lead pencil. After a few tries, I had come to an approximate equivalent resistance and I was the proud owner of a working and mercifully SILENT countdown stopwatch.
    It was a cheap, on-the-spot, hack that worked. 10 years later the stopwatch still functions.
    Total cost of the fix: zero. Satisfaction: priceless…

  14. orange says:

    Woot!

  15. MesmserizeOwner says:

    Samsung Mesmerize owner here. Doesn’t the “Take out the battery, hold down VOLDown and plug in” method bring the phone into download mode for this variant as well?

  16. varg says:

    This is the kind of stuff hackaday is all about. Impressive.

  17. stompyonos says:

    Hello,

    I am the one who originally made this. Just deleted my old youtube channel not realizing that it made it on here.

    I am making a new channel with hopefully more interesting stuff. I’ll try to find the video and re-upload it. I’ll send the link when I do, I hate broken links and now I feel bad contributing to the problem.

    At the time the phone was still worth a bit and I do have a whole bunch of resistors now. I was just starting out with electronics, and the nearest decent electronics store is around 50KM away from here unfortunately, which I didn’t even know of at the time (radioshack -> the source turnover was not kind to hobbyists). The only option I knew of was to mail order some, but didn’t have the patience to go days without my phone.

    I spent the night ripping apart old amps and radios looking for resistors that I could chain together to make the correct resistance with no luck. So I was lying in my bed, thinking, there must be a way to do it. And this is what I came up with, which worked.

    You must clip the wire under the paper clip firmly otherwise the values jump around too much when the wire is moved, but other than that it works great.
    The hardest part was ripping the rubber off of an old nokia plug.

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