F100 Mk2 Dpad Mod

[doc5avage]

So I took the plunge yesterday. Originally I was going to wait until I had my pandora, but I was bored.

I dropped into my local pawn broker and picked up a half decent Nintend Gamecube Controller. Thanks to grahf for pictures posted and inspiration.

I gutted the controller, dremeled the dpad board and within a few hours I was ready to remove the old stick. There is nothing I hate more than attempting to do something without the right tools, but I am not doing to well financially, so I had to make do. My cheap arse solder pump did a lousy job at removing the solder, and I didn't had side cutters fine enough to get at the legs. Needless to say it took me a long time to remove the stick, but I got it out, and amazingly the board still functions afterward.

I used the 3m double sided tape, also as suggested by grahf, which worked a treat.
The hardest part of this mod, is figuring out how to put the gp2x back together.

Finally it is back together, and the buttons are registering perfectly in the gp2xmenu and in the gp2x test mode.
Gmenu2x works fine too.

But not games.

WHAT????
Example: Alexkidd2x-->AlexKidd Alex is always running left
DrPocketSnes-->Super Mario Allstarts-->SMB1--> Game seems to operate perfectly, but if I jump without pressing any d keys mario goes to the left, as if blown by a big fan.
GnGeo2x-->Blazing star-->Ship is always traveling down to the left.

I knew there was the possibility of breaking my machine, but I was hopefull and could fall back onto my psp if necessary

Can anyone help me?? What have I done wrong, for the buttons to register correctly in the menu's, but fail in the games?

Thanks for listening.

 

[trooper]

I could be wrong, But it sound as though you may have a button stuck down somewhere.

Have you tested your GP2x on the built-in hardware test screens since doing the mod ?.

Trooper

 

[BobBorakovitz]

hey, I had similar problems on mine. My problem was that the double sided tape was too thick with the circuit board, the rubber membrane, and the dpad in it. I'd try to first get some thinner double sided tape and see how that goes. You could also leave the system apart and turn it on to see if everything functions correctly without being squished together.

Good luck, you're almost there, just time to do some tweaking!

 

[grahf]

Try what Bob suggested. Its going to take a lot of fine adjusting to get it perfect.

Also, note that in my pics I posted that I used two red wires. They switch as they are going over the top of the pcb. I dont know if you used that pic as a guide, but just thought i'd mention it.

 

[doc5avage]

Thanks Bob and grahf,

grahf: I did try to use your pic, but ended up just running some wires across the pcb while it was running to see what switches what. I assumed that because the gp2x test mode was fine, that everything else would be too.

Bob: I used 2mm thick double sided tape. How thin was the dpad once you had shaved it right down? I will try thinner tape as it does feel a little too tight.

On a side note, the gp2x main pcd is freaking solid!!! I had a hell of a time getting the old stick out (not the right tools), but it still withstood my beating.
I was fully convinced that the board would not work, after what I had done to it.

 

[bacteria]

Sand a millimeter off the thickness of the mobo (using a sanding block or Dremel), the traces are at the top of the board after all. This will help things to fit. Make sure you wear a mask and have the window open when you do this though!

 

[doc5avage]

Okay, I ripped it apart and tested drpocketsnes without the case on, so there are no buttons being pushed continuously. In the DrPocketSnes menu, everything seems fine. But in a game (Tetris Attack), the menu's act as if down is being held on.

I know this has to have something to do with my wiring, but I don't understand how. There is something fundamentally different between how menu's and gp2xmenu Test mode vs games (esp. emulated) react to my wiring.

grahf, I didn't use your wiring because my gp2x board did not seem to have the pinouts in the same places, so I had to guess.

I am going to take a photo of my gp2x board, and hopefully bacteria, grahf or someone else can help me out.

Cheers

 

[doc5avage]

Here are the pics. All of my wires are different colours, so it should be easy to make out where they are going.
The back of the gp2x looks like I have brutalized it, again, this is because I didn't have the right tools.

Green -->Right
Red-->Down
White-->Left
Yellow-->Up
Blue-->Close circuit (or whatever, unknown to me)

I know in this photo some of the joins look faulty and like they are touching other contacts. I can assure you that they are not. I believe this is where they are wired incorrectly, most likely that I have got the blue wire in the wrong spot.

 

[doc5avage]

It is becoming clear to me that my gp2x stick pinout on pcb is different to grahf's.
Was there a change in pcb from mk1 to mk2?

Okay, here is the deal.
My gp2x is fubar'ed.

I de-soldered everything that I added, so it is just straight pcb. And in emulators, it is as if back is being pressed continually.

What could cause this?

 

[BobBorakovitz]

well, I'm not sure of your pinouts, but by looking at your pics, I'd say start at your solder points. a couple of them look they look like they are touching, and that could be what is going on. I'd start trying to desolder those bad connections.

Did you use flux to help keep the solder only where you want it? Also, another tip is to use clear nail polish over close points you don't want to bridge.

The way I understand how emulators work with the GP2x controls are that they combine left and left up, for example, into left. This is due to gp2x's 16-way joystick and most everything emulated uses an 8-way.

 

[doc5avage]

So it was 16 way? And now I am going 4 way.

 

[grahf]

My gp2x is a mk1, so if yours is a mk2 then its definitely different. The joysticks were rotated 45degrees for the mk2s. From my recollection, what happened was this; DaveC was the first person on these forums to look into joystick improvements, and after dissecting a stick he found that the 1st gen units had a large diagonal bias. I believe Craig passed the info along to GPH, who rotated the stick 45degrees for the mk2 units. So the pinout between mk1/mk2 is the same, just rotated a bit.

I would double check everywhere to make sure nothing is shorted. Desolder the holes as best you can. The direction pins have 3~5v in them, which is grounded upon direction presses. Perhaps one of them is shorted slightly to the ground plane.

 

[BobBorakovitz]

So it was 16 way? And now I am going 4 way.

not quite, you went from a 16-way to an 8-way. Although you are using only 4 actual directions now, you can press 2 at a time for diagonals, which count as another 4 directions.

 

[doc5avage]

Yay, I fixed the problem! Althought I don't know what was causing it.

This morning I cleaned up the joints and set out with a multimeter to find the correct points. What I found was inconclusive and seemed to indicate that my setup was okay, but still every game shows that 'back' is being pushed.

Mucking about with a peace of wire, I found the only way to stop it was by shorting two of the points. (I couldn't figure out why, or what they were for though), then I powered up my gp2x again only to see the gp2x screen, then it when fuzzy (like noise in it), then freeze.

I was about to post here, saying game over. GP2X dead.
As I was typing my sob story I realized that I had put batteries in it that had been playing up recently. So I changed the batteries and it came alive again.

This time, did some more test, cursed some more, then removed my short (Which was preventing 'Up' from working)

I tested again, this time, 'back' was not being pushed. YAY!!

So now, my gp2x is back together with a semi-working dpad mod. I say semi, because it is still a little too tight, I need to get that thinner double sided tape.

Thanks guys

 

[grahf]

Glad to hear its going again. It might have been something as simple as a random stray spec of solder that was shorting something.

Try loosening the screws a little bit in the back until the control improves. If you go check the seam between the case halves, and you can tell just exactly how much more you need to shave.

 

[BobBorakovitz]

Yay, I fixed the problem! Althought I don't know what was causing it.

.................etc.................

Thanks guys

congrats! you should be able to tweak it to working correctly closed now. Sorry I can't tell you the name of the double sided tape I used. It was something my dad had around. I had originally bought some 3m stuff that was like a foam that was too thick. The stuff I ended up using looked like duct tape, but was brown and double sided. Much thinner.

Good luck and keep us updated! Don't forget the pics of the finished job!

 

[palmertech]

I had a simalar problem, all my directions work in test mode and the menu, but they freeze in emulators! However, they work fine in doom... Any tips?

 

[doc5avage]

Pull it all apart and do it again.
Worked for me.

 

[doc5avage]

Getting closer. I have enough space in there now, but I'm having an issue with the Gamecube PCB.
The up direction gets pushed if you breath on it. Seriously, if I have the case off, and I breath on the pcb 'up' gets pushed.
Problem is, that this makes games oversensitive to the 'up' button.

I have tried cleaning the contact with Q tips and metho, but this did not fix it. Can I try sanding it with light sand paper? or Will I have to replace this board? I can easily get hold of another board, but if sanding it or something else can fix it, then I would prefer that.

The up contact looks just as good as the other contacts, so I can't see where it is bridging.

 

[BobBorakovitz]

I think mine did that. I ended up using a membrane from a NES controller.