Weird touch behavior

Hi guys, i am coming back at you again with my broken almost fixed switches :slight_smile: One of them is fully functional, no more issue. On the one that had the battery connector with broken solders, i have a weird issue on the touchscreen that i didn’t noticed at first.
I only have part of the screen that works as intended, the left one. The middle is not responsive at all, unless i cover the complete screen with my hand, then it detects some touch, the right part does behave correctly as the left one, but on a smaller area.
I checked the connector inside that goes on the cartridge module, i redid all the solders of the ribbon digitizer cable, i cleaned everything with alcohol, didn’t notice any improvement. I read some posts to calibrate the touchscreen using Hekate, is that my next move or do you advice me to look something else first ? Thanks for the advises.

I would say it is either a damaged digitizer, or something wrong on the cartridge module. This is where having a working but really scratched old digitizer to hand is useful to test. Assuming you dont have one you could swap in a known working board to at least rule that out?

There is also some GC PCB’s which are incompatiable with some digitizer versions, some digitizers have the Bar/QR printed on the digitizer ribbon and some have a number printed on them, I beleive this indicates the version. If it’s incompatiable you’ll get touch only around the outer edge of the digitizer.

Though, there are also cases where a fault on the GC PCB can cause similar symptoms, I had one where when I put pressure on the single screw hole it would magically come back to life and started working, I assumed VIA damage and transferred the IC onto another PCB but had the same symptoms, very strange. I’ve also had cases where the vias at the GC PCB connector are corroded away and repairs are needed to restore touch, and of course there is the common fault where the connector which connects to the mainboard is warped and just simply needs bent so it can make proper contact again

Thanks guys, some feedback after my last checks, cartridge port is working fine, i played Zelda BOTW for 3h without a single glitch. I inspected the port on the main motherboard, all looks fine, same goes for the ribbon connector that comes from the GC PCB. I inverted GC boards from a good working Switch with that one, problem inverted as well. So the digitizer is good and the GC board have something, but i can’t figure out what. I put some pressure around IC, screw that you mentioned Severence and so on, nothing to do, it doesn’t work. Can we exchange safely those board without any problem, or does it require any specific programming ? Perhaps i could also try to use my hot air gun on the IC because some soldering are failing ?

I see, it may just be a dead IC which is what I suspect the one with issues I mentioned earlier had as I never did resolve the problem with it as all Vias and connections were fine, I get the feeling my finger being in that particular spot was altering something electrically rather than physically in that case.

They are interchangeble between boards provided they are compatiable with the digitizer revision, I have had several which will only work with the QR code digi and vice versa

You can try the troublesome GC module in Hekate and see if all touch functionality works as it should, if it all works fine then it may be pointing to a digitizer incompatibility rather than any physical problems. If touch is exhibiting the same bad symptoms in Hekate then you can safely say the GC board or IC itself is at fault.

There’s no way to reprogram these IC’s as far as I’m aware unfortunately.

I just bought the 2 versions online to have a look, i will give a try to Hekate as well, but is it necessary to have a Windows system or can we do it through Linux as well ? As far as i can remember, it is just an archive that we need to extract to a SD card and then use a jig to exploit the Switch right ?

On Windows you’d use TegraRCMGUI to inject the Hekate payloaf I’m pretty sure there is a Linux equivelent tool

Yeah just put the files on the SD insert the jig hold the button combo to get into RCM then inject the Hekate payload :slight_smile:

And here is the Linux tool in case people are interested, I will check this on Monday evening and will let you know. https : / / github . com/nh-server/fusee-interfacee-tk

Hi guys, wanted to give you feedback now that i received the new game card and touchscreen controller board, all the touchscreen was working again without any issue.
I had a strange behavior not related to this, because also present with the older one, that the console was crashing with error 21001-000 and rebooting.
I didn’t found any reason for this, but after opening the CPU cover to check under, i noticed that there was a big flux accumulation around the RAM modules, which could i guess make this kind of instability.
i cleaned everything many time, and tried to reassemble everything, and i broke the LCD connector (Y) (dumb of the year hello).
Well, still a rookie and learning about micro-soldering and fixing Nintendo Switch so, i guess you can’t make eggs without breaking them…
Anyway, i wanted your advice about the way to replace this LCD flex connector. I notice on many Youtube video that they apply hot air from beneath the board, but i am wondering, how is it possible that the components on the back of the board doesn’t fall ? https : // www .youtube.com/watch?v=-Sbh6f2l4HQ Is it because of temperature and air flow, or no matter the heat you would apply, they wouldn’t fall ? I need some advice here, especially what are the common temp/air flow you use guys, that would be great. I know it is also depending on the hardware you use, but at least some guidance, i haven’t found similar post around and when i searched about this topic, i found many many different results out there … Thanks.

The components on the bottom are held on with the surface tension of the solder. You have to be a bit careful not to knock it while it is molten, and I have had issues with magnetic holders occasionally stealing things that were too close to the magnets. That said usually things stay where they are meant to.

Hey,

great news man :+1: what about the old GC PCB did you have any joy with that and the new digitizers? or were they all the same rev touchscreens you ordered?

The flux being wicked up through the shield is usually as a result of people pointing the gun towards the shield during M92 rework instead of away from it, if the shield frame is rusting or of the nickel plating is coming off then thats also an indication of over rework and/or too high temp whilst pointing hot air in the wrong direction.

The error code your seeing is very likely as a result of bad M92 IC install, either because of bridging between pads/pins and/or the surrounding components or because of IC pins on this IC not making proper contact with the board.

As for the LCD conn, after it’s removal you’ll be priming the pads with leaded solder which typically has a reflow temp of about 180C, the original lead free solder is approx 230/250C so an approx 40C difference which will prevent components falling off during rework of new connector provided your using low air and don’t linger, on my station I’m typically using about 420C in this process

Thank you both for your excellent advise, i will give it a try with another board that has some traces and pads knocked-off on the USB-C connector, so that i don’t feel sorry if i break everything :smiley:
About your question Severence on the digitizer, i didn’t replaced it. Basically on the 3 Switches i tried, the original GC PCB was failing with the center of the touchscreen and correctly was reading the game cartridges. I ordered 2 new on AliExpress from “different revision”, and both of them worked. I must admit that even under the microscope, i wasn’t able to spot the difference between the 2 new board. But at least, they are working, so when i will succeed in replacing the LCD connector, it might turn into a working Switch again :slight_smile: