right trigger always pressed

[tedris]

Hi there,

i bought a used, "broken", x1 controller.

It was mentioned that the right analog stick and the right trigger arent working properly.
I already fixed the analogstick, but i havent had luck with the trigger so far.

I measured the voltage of both hall effect sensors and both seem to work fine (about 270mV when not pressed, decreasing when pressed).

I cant see any shorts on the pcb itself..



Any ideas?

(i want to use this controller as a padhack arcade stick btw)

[tedris]

Or can anyone tell me what i need to do to "shut off " the right analog trigger and modify it so i can use it as a normal button for the arcade stick?

thanks

[tedris]

Ok, since no one has a solution to this either, i guess i just throw it away..

[RDC]

The pic doesn't really help much.

Measure the voltage after R39 (RT) and R38 (LT) and compare them there.

If they are about the same there, then it could be a bad trace between the Hall and MCU, or the MCU itself is knackered.

If they measure different there, suspect R39 is open or way out of spec.

If RT acts pulled all the time suspect C36 is shorted, the line to the MCU is shorted or the MCU is again knackered.

If you're still going to bin the thing, then send it my way, I'd like to see if the MCU is bad by swapping it with a known good one to at least nail the issue down.

[tedris]

Hi RDC, thanks for your reply.

R39 measures 268mV, R42(i think u meant that for LT) 268mV (both in state when the trigger is mechanically not pressed, both with decreasing voltage when i pull the triggers).

As i will use this controller for an arcade stick i dont need the halls, but i think thats not the problem as is seems to work fine.

can i just desolder the C36 to resolve this (unless its a shorted line to the MCU)?

I live in germany, soo sending it to you would mean serious costs

[RDC]

Yeah R42, I got that and C38 over there mixed up.

You can remove C36, it's not going to hurt anything, but it's probably also not going to correct it since the voltages measure the same.

If you can check the voltages of the MCU (U1) at pin 20 (for RT) and pin 72 (for LT) then you'll know if they are at least getting there, and if they are there, then the MCU is most likely messed up internally and there's really nothing to do then.

[tedris]

Pin 20(RT): 90mV when not pressed, 90mV when pressed
Pin 72(LT): 270mV when not pressed, 91mV when pressed

i think we can safely say that the MCU is ok. there must be a short then.

i will upload a picture soon i think i found the bad trace, but dont know how i can fix this

EDIT:
It seems like if there was a crack, dont know how it happened but the reflection assumes it


here the via i believe is the issue, its hard to photograph it though

[tedris]

I just found its not a short, its a bad trace. if i connect c36 to pin 20 it works fine.
so the "pink" trace has a problem somewhere.

unfortunately i havent got a decent solderjoint to pin 20 yet without accidentially touchen 19 or 21 with tin 

[RDC]

19 and 21 are the Right Stick lines, so you'll want to stay away from them.

I'd repair the trace at the break, along with any others that look broken there.

http://forums.xbox-scene.com/index.php?/topic/684774-repairing-those-tiny-motherboard-traces/

http://forums.xbox-scene.com/index.php?/topic/512248-broken-trace/#entry3406983