Hardware Designing a flexboard for easier USB C port replacement

[sImasC]

Hi,
This morning I had some kind of idea under the shower...
A weak point of the USB C port is that it is soldered directly to the motherboard. The exchange is only possible with hot air and the risk that the motherboard takes additional damage. Over the lifetime of your switch you may want to replace the port several times if it gets defective again. Each time you risk your mainboard again.
In other mobile devices these critical components are located on a separate board which is connected to the mainboard with a ribbon cable. In Lenovo ThinkPads, for example, the power socket is very easy to replace in this way.

My question now is whether there is enough space above the USB socket to mount it upside down with a flexboard. I have prepared some very basic concept drawings. The flexboard would have through-holes to solder it to the PCB and then onto the usb port.

If my idea would work, replacing a defective port would work like this:
1) The connector can be carefully crushed out with pliers until the pins are free.
2) Use a solderiron to remove the pins from the switch PCB
3) Solder on the flexboard onto the Switch PCB
4) Solder in two small copper plates
5) Align the USB port upside-down between the copper plates, so that it later fits into the dock
6) secure it by soldering it onto the copper plates
7) Bend the flexboard onto the pins of the usb port and solder it in place

Advantages
Simple assembly and in the future only the flex board will be soldered, not the motherboard.

Disadvantage
Alignment of the usb port may be a little bit more tricky to hits the dock in correct angle
Maybe also the mechanical stability is not as robust as in original

Risks
USB 1 und 2 war immer etwas empfindlich, wenn in der Führung der Leiterbahnen etwas verändert wurde. Beim Design von Platinen sollten zum Beispiel Durchkontaktierungen vermieden werden, damit es zu keinen Störungen kommt. Ihr kennt das, dass manche Geräte mit langen USB Kabeln nicht zurecht kommen, das wäre solch ein Effekt.

There will be no problems loading the switch, but it is possible that the TV output may not always work properly. This should be shown in a practical test.

My personal background:
I am an electrical engineer, I have already designed many boards for microcontrollers, routed and etched them myself. I have not yet developed flex conductors myself. I'd have to get used to this for me new topic.
I usually do 3D designs with FreeCad, this may also help for further development.

What I would need:
- Information about the space above the usb port (maybe there are some 3D models in the web of replacement Switch cases we could use)
- Exact design or 3D model of the original USB port
- scan of the Switch PCB to design the flexboard onto it for easy soldering

Regards
sImasC

 

[TariqSoftDev]

1) Don't crush off ports with pliers the pads are not extra strong or anything and will break.
2) This will make the port less durable.
3) You're better off doing a proper replacement rather than adding a flex.

By all means do this but you'll end up either damaging the board or destroying it; no point.

 

[sImasC]

Ripping off the SMD pads would damage the board. The idea is to destroy the port without any stress to the smd pins to be able to unsolder the rest with a standard soldering iron.

If I watch the videos on youtube, people do have a lot of problems getting the inner pins resoldered. They heat up the mainboard again and again. At the end the new port is mounted but the parts around got melted - even if they used capton tape. Yes - it is for sure better to replace the port with hot air or a reflow station. But also if you buy this tools you need some time an experience to handle them correct.

Multilayer boards don't like it if they are heated up too often or too hot. I see here the main cause for mainboard damages.

The original connector seems to have 4 ground connectors in its edges and the two screw holes. After I saw this I don't think it is less durable, this mechanical connection points can be reused.


But at the end of the day I found the real point why it is game over here. The port sits in the middle of the PCB. By mounting it upside-down it would sit on abve the PCB and therefore would not align with the housing and the dock.

 

[gamesquest1]

yeah, would be nice if nintendo had made the port a little easier to replace, most mobile phones etc at this point have realised that its much better to have ports on a separate daughterboard or flex cable, its not exactly impossible that nintendo could redesign the motherboard a little and make it easier to repair, but assuming you have a bit of experience its not too difficult to replace the USB port, hopefully once you break the port once when its replaced you are a lot more careful going forwards

 

[ghjfdtg]

I wonder how people even break these. USB C is supposed to be much more durable than micro USB and i have not broken a single one of these yet. Are they throwing their Switches careless into the dock or something?

 

[mattytrog]

1) Get board in a vice "facing you"... ie all ribbon connectors are on top and visible
2) Heat broken USB port up from underneath. About 380 degrees. Don`t knock the decoupling caps or filters/ferrites on PI3USB
3) Lift off
4) Blob a load of mega poisonous leaded solder on the pads
5) Use some Chemwik to mop it up. Bit of alcohol / flux cleaner to polish the pads up.
6) Fresh bead of solder. Not much, just so pins are shiny. Bit of no clean flux on back of port. TK83.
7) Heat up from underside, you will see each trace "become shiny". Once all are shiny including mounting holes, dab on. Stick a pair of tweezers through the screw holes and the new port if you like to assist with alignment. The tapered action of tweezers will ensure the holes line up
8) Hold heat on there 5 seconds... Remove heat, clean residue.

Done.
Test continuity.

 

[sImasC]

I wonder how people even break these. ...

levering force and for sure the kids will throw the console into the dock. The 10 year old son of a friend has also half killed his port, charging only works if he bends the usb cable in one direction. He now plays with his switch until the port is completely dead, then I will get it for repair. I will then buy a hot air soldering station and train myself with old computer mainboards before I give the sitwch a try.
For my personal projects I always used USB B connectors, these seem to be the most robust to me and exchanging is no problem.
The second best solution are gold contacts for charging like on the WiiU pad and old mobile phones. I've never seen broken contacts.
A magnet connector would also be a nice solution, but way too much contacts for USB C interface.
But not using a separate PCB for the stressed connectors is a shame!

1) ...
2) ... About 380 degrees. ...
4) Blob a load of mega poisonous leaded solder on the pads
...

Thanks for the detailed repair steps and the temperature hint. I wonder why there is no tutorial at ifixit for the usb port, yet.

And yes, nothing is better than soldering with lead

 

[ghjfdtg]

Yeah, that's what i thought. micro USB and even mini USB is piss easy and you can get them off the board with the soldering iron alone (not exactly recommended but done in under a minute with a good soldering station). I have not dealt with USB C yet but seen Videos on these. It's a nightmare with the hidden pins. No chance without hot air. Not having the connector on a separate board is really annoying.