JDM-040 - Left stick and Trigger Problem

[aydinrad]

Hello guys,

A few days back, I decided I would try to adjust the potentiometer position in order to perfectly center my left stick. Along the way, I accidentally tore a trace on the y-axis potentiometer:



Here's the other side of the board



I figured I could just wire a jumper cable on the actual joystick from the lower y-axis potentiometer pin to the right x-axis potentiometer pin. However, after plugging in the controller without the left joystick in at all, the joystick (despite the controller not having one soldered in) just wiggles around the upper left area. Also, l2 and r2 act as if someone is repeatedly pushing them halfway down and then all the way down repeatedly.



The strangest thing is that if I fully depress l2, the left stick shoots all the way to the top left. What's going on here? Shouldn't the left stick be completely neutral, since no stick is attached at all?

I am unsure as to where to go from here, as installing a joystick and jumping the two pins described above doesn't fix the problem. Do I need to use magnet wire underneath the joystick instead of using a jumper on the actual pins of the potentiometers?
 

[RDC]

With no Stick installed the LSX and LSY lines are floating, they have no defined voltage on them now, so they will do all manner of weird things.

Sometimes if the controller isn't all the way together the connection between the main board and daughter board isn't tight enough and can also cause weird issues.

[aydinrad]

Ok, so how should I go about fixing the torn trace? Is it enough to attach a jumper like this onto the joystick?



Or should I run a super small wire (like a magnet wire or something) like this on the other side?

[RDC]

Jumper wire on the bottom will be fine, just make sure the battery tray or case doesn't pinch it anywhere when it's closed up.

[aydinrad]

I have just gotten finished attaching the joystick back and putting in the jumper cable. The left stick acts totally normal, but l2 and r2 are still totally freaking out. I am able to fully depress the triggers and have them show up as fully pressed, but when the triggers are not held down, they are moving all over the place in my gamepad tester. I have already cleaned the contacts of the ribbon circuit and l2/r2 contacts and changed the wipers inside the left stick. Any idea what the issue could be now?

[aydinrad]

Here's a photo of my work just in case there's something wrong here.

[RDC]

Possibly some corrosion of just some crud under the MCU there. Try getting some rubbing alcohol under there and blowing it out with some compressed air.

[wickated]

I have just gotten finished attaching the joystick back and putting in the jumper cable. The left stick acts totally normal, but l2 and r2 are still totally freaking out. I am able to fully depress the triggers and have them show up as fully pressed, but when the triggers are not held down, they are moving all over the place in my gamepad tester. I have already cleaned the contacts of the ribbon circuit and l2/r2 contacts and changed the wipers inside the left stick. Any idea what the issue could be now?

what voltage is on pots? 1,8 or 3,2v ?

[aydinrad]

Possibly some corrosion of just some crud under the MCU there. Try getting some rubbing alcohol under there and blowing it out with some compressed air.

Just did that and am still having the same issue.

what voltage is on pots? 1,8 or 3,2v ?

Measured 3.2V DC on all pots for both sticks.

[aydinrad]

Might this be a good time for me to invest in a heat gun and attempt to reflow the MCU?