Repair - Bent board, inputs dead

Discussion in '3DS - Console, Accessories and Hardware' started by Teki5, Oct 9, 2018.

  1. Teki5
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    Teki5 Member

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    Oct 20, 2016
    I bought a N3DSXL non working, intending to repair it or salvage parts. It was marked as "doesn't turn on, bottom shell missing, c-stick replaced" so I didn't expect anything particularly bad.
    However, what I found instead was a botched reassembly job (presumably after the C-stick mod). One of the cables going to the top half was in upside down, and most of the small connectors on the main board are damaged. But worst of all, the main board is physically bent (no visible splitting) and the SD card slot is crushed.

    After re-orienting the upside down cable, removing the SD card module and tidying up some other bits, the console is now able to turn on. However, almost none of the inputs seem to work, not even the volume slider. The A button has worked only once, the C-stick responds but often incorrectly, and the D-pad has also worked once.

    Given the somewhat intermittent functioning of some inputs, is this likely due to the SD card slot shorting out and damaging a chip, or is it more likely a cracked solder joint I could fix by straightening out the board and reflowing the relevant chip?

    I'd like to know if this board is worth working on, given that it still turns on and boots, or if I should scrap it and put the rest of the good parts aside as spares.
     
  2. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08

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    Very likely a cracked solder joint, or a physically lifted pad. But could still be a broken trace somewhere, it only takes a hairline fracture to break the connection. It could also be a component that was stressed enough from being bent that it broke internally. All those things are fixable if you have the skill, the hardest part is pinpointing the issue.
     
    Last edited by The Real Jdbye, Oct 9, 2018
  3. TurdPooCharger

    TurdPooCharger Meh

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    Wait, so are you able to boot into HOME Menu? Can you take some pictures of all the physical flaws within the n3DSXL?

    You should do a cost vs benefit analysis of the how much you'll spend in the end buying the various replacement parts and compare that against finding a used n3DSXL.
     
  4. Teki5
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    Teki5 Member

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    Oct 20, 2016
    A broken trace would be out of my repair skill set, but a solder joint I can have a go.

    It boots into the home menu, yes.

    I'm out at the moment, I'll post some photos later. The majority of the visible damage is scratches and scuffs on the case and the screen covers. The top screen has a slight defect in one corner that may or may not be repairable, the bottom screen has a few light spots where it's been pressed from behind by whatever bent the board. The SD card slot was fairly easy to straighten out to the point where it's not shorting anything and will accept a card.

    Aside from a replacement bottom shell and screws, and anything I might need to fix the screens, the only parts I'll have to buy are the tiny connectors. Those are very cheap on Mouser. The total cost of the console in this state was £32, so even if I have to spend a bit on it I'm still looking at a bit of profit. That is, if I can fix the inputs!
     
  5. ghjfdtg

    ghjfdtg GBAtemp Fan

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    For me this doesn't sound like it's worth to invest in. If the board was treated that badly it probably won't last very long even if you can repair the current defects. Especially the bent mainboard is a red flag.
     
    Last edited by ghjfdtg, Oct 9, 2018
  6. The Real Jdbye

    The Real Jdbye Always Remember 30/07/08

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    The problem I think would be pinpointing the solder joint, trace or component. If you don't know how to fault-find various types of components on a circuit you have pretty much no chance of pinpointing the issue except by luck. Even if it's a visible fault it could be hard to spot, but it's not necessarily visible.
    And even if you think you've found the issue, the only way to know is to attempt a repair, and if that doesn't help, you're looking for a needle in a haystack trying to find what apparent issue is actually causing the problem, and the more you have to plug and unplug ribbon cables or desolder and solder stuff, the higher the chances are of damaging pads, traces or ribbon cable connectors, damaging components by applying too much heat to them, or accidentally desoldering components next to what you're actually trying to desolder. There's just so much that can go wrong without a decent amount of experience working with boards like this.
    As long as the board and components are not subjected to additional stress, it probably won't just break suddenly. Trying to bend the board back into its original shape can cause additional stress though and leaving it in the bent shape isn't any better. If possible bending it back into the original shape is probably the best as that at least ensures there won't be constant stress on the components and traces.
     
  7. ghjfdtg

    ghjfdtg GBAtemp Fan

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    The problem i see are hidden cracks in traces and solder joints especially on BGA components. There are many components on the board not secured with epoxy. They may work now but start to make bad contact later on. Another thing is cracked ceramic capacitors. If they crack they tend to go nuclear and short to ground.

    I would not put much effort into it as said. If you can fix it, fine but i would not sell it without mentioning these defects.
     
  8. Teki5
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    Teki5 Member

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    Oct 20, 2016
    Thanks all.
    I'm doing this partly as a learning experience, so if I can't get a sellable unit from it I'd at least like to try figure it out. Especially since I already invested in it by buying it like this. Aside from that, like I said there are a few undamaged parts that should still be good as replacements for future repairs.
    Not directed at anyone in particular but in case it wasn't clear I'm doing this for the sake of repair experience rather than to get a console on the cheap. Profit or a spare console would just be a nice bonus.
     
  9. Teki5
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    Teki5 Member

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    Oct 20, 2016
    Here are the photos of the mainboard damage.
    Bend in board:
    DSC_0715.JPG
    It's curved along both directions by about the same amount (sort of dome shaped).

    Damaged connectors:
    DSC_0717.JPG DSC_0718.JPG
    Rightmost connector in the second picture, for the circle pad, had the clip on until I broke it, but circle pad was already unresponsive.
     
  10. TurdPooCharger

    TurdPooCharger Meh

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    Jan 1, 2018
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    Whoever was the previous owner that turned this n3DSXL into such a sad state that it's in is a truly PoS person because listing all the issues it has:
    • Shell: scratches and scuffs
    • C-stick module: FUBAR
    • SD card slot reader: crushed
    • XYBA daughter board: non-responsive
    • Speaker assembly: non-responsive 3D and volume switches
    • D-Pad assembly: non-responsive
    • motherboard: bent board, broken connectors + traces
    • Top LCD: corner glass nicked or crack??
    I don't see how restoration is going to be any cheaper than buying a used good condition n3DSXL. It's a small wonder how your's is still alive albeit non-functionally.

    You are basically replacing everything and only reusing the camera and a very questionable motherboard. Unless this specific 3DS has sentimental value that can't be measured in terms of £, like a gift from a long gone friend or a need to achieve zen with your inner modding spiriting, you should really reconsider ditching it.

    ***

    If you insist (trying to) save this very abused n3DSXL...
    I wouldn't bother bending the board back in shape as permanent deformation with brittle-like materials like silicon almost never works out when trying to re-straighten them. You'll likely crack it.

    To fix the connector(s), try swapping in missing flap piece from a replacement connector of the same type. If that doesn't work, there's also soldering an extended bypass from connector-to-connector. Another idea to try is hot gluing on top of the flex cable as a makeshaft clamp.

    As for everything else, it's disassemble and replace whole components.
     
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