Hardware Cursor going all over the place - HELP ME SUSS THIS OUT!

[jaisunny]

Argh having an absolute nightmare Sunday. Since 1pm for 4 hours solid and 5 hours in total i've been replacing the damaged top screen on my sons old 3ds XL and ive encountered a problem.

When i boot the 3DS up now (was working before) the cursor goes berserk... all over the place left right up down for 5 to 10 seconds then it starts going RIGHT > RIGHT > RIGHT all the way to the end and wont stop.

I've taken it all apart around 30 times now securing everything as i go, making sure no crap stuck under anywhere. My neck is literally killing me looking at all this time and i cannot for the living hell life of me suss this out.

So, I removed the top triggers, D pad and circle pad and booted it up to try and eradicate what is causing it and guess what? ITS STILL DOING IT with no control buttons attached!!!

SURELY the top screen isn't causing this???? as thats all i replaced.

So i attach them all back 1 by 1 and try to calibrate the touch screen which calibrated OK.
Then tried to calibrate the circle pad and it wont calibrate anymore. Just keeps saying " CALIBRATION FAILED ". During the manual calibration if i take the circle pad LEFT it shows LEFT on the screen, RIGHT shows RIGHT on the screen, DOWN and UP does absolutely nothing. SO i reinserted the ribbon for it and tried again, now its stuck in the RIGHT position on the manual calibration and wont move at all.

How has this become damaged? it is not looking damaged AT ALL and i was super careful removing this. Every time i take these 3DS's apart something goes wrong. I have a IT and mobile phone repair background so the 3DS should be a doddle for me, but it isn't.

Anyway. I've removed the circle pad completely since it wont calibrate, but on boot up the screen still goes everywhere.. left right, up down over and over for a good 5 seconds or so until it stops then i can control it OK with the D-PAD (doesn't keep going right right right right with the circle pad removed. But if i go into a game, pokemon moon for example, on the map where you can move the cursor around, the cursor is just going UP the whole time. and i have to keep pushing the D-pad down, if i let go it goes back UP again.

What the hell is happening?

 

[gamesquest1]

its the analogue stick, if its not inserted correctly it will default to "right", try reseating the cable, if that fails you may need a new analogue stick they are fairly cheap and easy to install

PS double check the pins on the connector for the circle pad and made sure you haven't bent/snapped any of them

 

[jaisunny]

its the analogue stick, if its not inserted correctly it will default to "right", try reseating the cable, if that fails you may need a new analogue stick they are fairly cheap and easy to install

But with it removed why when booted up the cursor goes all over the place then settles down after 5 to 10 seconds?

Also whey in a game is the cursor going UP UP UP UP constantly?. But in the main menu the cursor is OK after its had its 10 second fit.

 

[jaisunny]

Ive looked at the pins on the ribbon for the analogue stick on a magnify glass and they looked perfect.

However, i've wedged a foam double sided tape a few MM thick between the ribbon cable port and the analogue stick and screwed it down with those 2 screws = Problem solved.

I THINK the problem was the ribbon cable lock a little loose but hard to tell that it was.

 

[DeoNaught]

EDIT: oof, nvm

 

[dsearnack]

just curious... you need to take apart the bottom to get at the top screen right? Haven't "gone up top" yet but when i did my qi charging mod and bluetooth mod there was some pressure created on the bottom touch screen and I experienced the same frustrating RIGHT>RIGHT >RIGHT> of the screen
when opening it back up next time look under the touchscreen near the "right"
anything near the "stylus tray" on the outside of that plastic,behind power switch, running up to the lanyard semicircle on the back - im thinking some pressure somewhere is casing it to think there is part of the screen pressed