Issues regarding LED mod on Qanba Q4RAF

I recently got the aforementioned arcade stick modded with LEDs and seem to be experiencing some trouble with the Xbox 360 mode. when the stick is plugged in, the two buttons on the bottom left of the stick (RT/LT) seem to be working in reverse. while the ps3 mode appears to be working normally, these two buttons remain dimly lit, and only turn off only when the button is pressed. they also seem to be permanently held down when playing a game.

has anyone experienced this issue before and is there any solution?

thank you in advance for your time.

haha i know this answer

it was suspected that the triggers for the sun-ga boards are inverted. In other words, they work in reverse of a button. You’d have to go and put a hex inverter in there to reverse the signal for a push to light setup for the xbox side of the board

only in xbox mode eh?
i would have thought the ps3 daughter side was inverted too

well, i don’t currently own a ps3 to check, but if the LEDs are anything to go by, they seem work correctly in ps3 mode when powered on.

also thanks a lot for your speedy response. i really appreciate it.

Can toodles hex inverter trick work on this?

Could you expand a little more on what you mean by this? Thanks

that’s what i’m thinking

just no one but missingperson has had the board to test

There’s at least two different versions of PCB in the Qanba’s; there’s the one with the SunGa daughterboard, and the one I have has it all consolidated into a single board with no epoxy blob. Drop One, could you post a photo of the board used in your Qanba?

The unfortunate fact is that we can be fairly sure that you’re in a weird spot if it works fine in PS3 mode but not Xbox360. You could do a hex inverter like networkingyuppy said, but that wouldn’t fix it, just switch which mode works and which is backwards. Getting it to work properly in both modes would take a little bit of hackery, probably tapping the ‘Xbox360 or PS3’ signal between the slide switch and the main board, and running each trigger through a XOR or XNOR gate before sending it to the LED mod. I don’t think there is an easier fix, and I do know that isn’t an easy fix for many folks.

Hmmm, could he just cut the traces going from the XBOX to PS3 with respect to the triggers and do the inverter mod connecting it to the inputs that way?

That’s the one with the SunGa daughterboard mr.mortified was talking about. Sadly, I cant be of too much help with that since I dont have one here to play with.
If you can find the spot(s) on that board that deal with the PS3/360 slider switch, and see what voltages they are at for each position of the slider, I can try to describe the XOR or XNOR chip setup I was talking about, but its still an out of the ordinary mod. You may want to get a pro to do it for you.

Hey guys. I’ve just run into the same problem after modding my stick with the SparkyJr PWM and Arceye2s.
In PS3 mode it works fine, but in 360 mode it hangs on yellow when loading (it normally goes red, yellow, green, off). This normally happens when you press down a button.

If anyone has any suggestions on how to help with this problem I’d be super grateful.

Edit: I’ve come up with an idea. Since I’m using a SparkyJr PWM which is reprogrammable I’ve asked 32teeth if he could write a patch to invert the buttons in the code if they’re detected as being held down when it starts up. This way the buttons will be dark when they’re “high” and bright when they’re “low”.

Might work, who knows.

So before I hack into this one this weekend am I going to run into problems?

You will, for the Triggers.

well fuck me… okay… this will be fun…

You sure man? I know the SunGa one has the flipped 360 triggers, but I think that one is fully common ground.

just have some fun testing
grab a beer and enjoy the multimeter beeping

thats exactly what I plan to do… the board is set up similar to the pdp with each button having a ground pin next to it… I’ll keep you all posted…

Yes, I’ve mod this.

I just pulled out mine, and it’s the same PCB revision as the one pictured (KC-0123A-A1) but it has an actual chip instead of the black epoxy wafer. The GND wire the goes with each signal is true ground, connected to the USB shield and black wire. There shouldnt be any trigger work needed for that board.

How many revisions will they keep doing?
The one I modified had Triggers going to VCC.