If I've got a SHORT, how come its still working?

[HeadRusch]

My Problem:  
4 player control panel.  
Player 1 and 2 each have 1 stick and 6 buttons.  Player 1 is bi-wired to a 4 way stick also on the panel.

Players 3 and 4 each have 1 stick and 5 buttons each, the 5th button for each station is on top of the joystick.

Players 1 and 2 joysticks, each with 6buttons, seem to be working fine.  Coin, Start also appear to be working fine.   Players 3 and 4 sticks appear to be working fine, although I noticed in x-men I had to re-map the keys for the player 4 joystick (HMMMMM).  it wasn't responding until I tabbed out to remap.

However, the top buttons on the joysticks...and the extra buttons I wired to Player 4 buttons 7 and 8 simply do not register, its like the IPAC can't see them.

Now, the plot gets weirder: Right now I think I have a short somewhere, as I'm getting current flow from EVERY CONTACT ON MY BOARD.  

If I single out a button, say player 1 button 1...and I put the leads on the NO and GND contacts, I AM GETTING FLOW and the button is not depressed.

I can touch the leads to the top of the IPAC between any of the 2 buttons...and get current flow!

BUT THEN WHY IS THE DARNED PANEL STILL, for the most part, WORKING!?!?!?!?!?!?

Could the IPAC be suspect?  If I take the button in question out of the circuit and test the switch itself, the switch is good..no current flows between NO and GND until I press the button.

how do I even begin to check this?

[BeBoxer]

The I-PAC is pretty good about detecting shorts on it's own. Follow the test procedure outlined on the Ultimarc web page, which I will plagerize here. When you enter test mode, if any buttons are shorted out it'll just tell you.

The following applies only to board shipped after 15th April 2002.
Boot PC into DOS or Windows and run a text program such as Notepad. If in DOS, enter COPY CON to suppress the command prompt. On a keyboard plugged into the pass-through, press CTRL-ALT-P. (press and hold each key in this order). If the MAME/ALT jumper is set to MAME, the unit will go into test mode. If not, enter "T" in the menu to enter test mode. All pressed buttons and joysticks will be displayed on the screen. The input will be shown, followed by the code which is currently assigned, followed by the shifted code, if one is assigned. Test all buttons and joystick switches. If all OK reboot to exit. Now ready to play!

If that doesn't help, we'll need more information. First off, it doesn't sound to me like you are actually measuring "flow" where "flow" refers to current flow measured in amps. There isn't ever any significant amount of current running thru your control panel if your lucky.

Normally you'd measure volts or ohms to find a short. If a button isn't being pressed, you should measure about 5V between GND and NO on the switch. Alternatively, you should measure basically infinite resistance (ohms). If the button is being pressed, you should see 0V and 0 ohms between the GND and NO contacts.

[HeadRusch]

Thanks beboxer...its been awhile since my "basic electrical" class in college....the only thing I took outta that class were some vague references to OHM's law and "if you ever feel like doing anything electrical in your own home, don't, you'll probably kill yourself the minute you turn on the switch".

My little $5.00 voltmeter is set to read continuity.....for example, red lead on NC and black lead on ground and boom, the numbers take off (then start to drop as the batteries try to push as much as they can).
Then, touching NO....no flow.  Until I press the button, circuit is closed, and I get readings.  "Good Switch" I say.

But on the IPAC, right now with it connected, I can touch ANY LEADS AT ALL and I get current flowing.
Obviously I'm not testing grounds here since those ARE all daisy-chained together I always get flow from one ground to another.

But.....if I put one lead on, say, Player 1 joystick LEFT on the IPAC (On the screw that holds down the wire), and another lead on...say......oh....Player 3 button 1, I read a current flowing.

Shouldn't I NEVER see any current flow between any two switches that are normally Open??
Thats where I think something is amok, unless I've forgotton my basic electrical principles (Which I may have!).

Seems to be I should never be able to see any current (I'm using the term generically) flowing between any 2 buttons on the ipaq, as I thought each individual button was its own unique circuit...?

Anyhoooo, I'm off to check out the test program on andy's site.

[HeadRusch]

UPDATE:There is definately something "UP" With either my IPAC or the new Windows utility.

Using Ctrl ALT P and putting the Ipac into test mode, ALL MY BUTTONS register......however, when using the WinIPAC utility, I cannot assign any inputs at ALL to buttons 5-8 on players 3 and 4....press the button, and I press any keyboard button, and it wont register.

Also, on player 1 and 2 you can right mouse click on a button on the GUI and select a function like APPLICATION or POWER, as is detailed in Andy's writeup of the new release....but if you try that on player 3 or 4 inputs, no dice.  I'm not sure if its designed that way or just an oversight.

Anyhow, I'm going to try programming with the DOS version.

The annoying thing is that even with the jumper set to default MAME settings, I STILL can't use those buttons when using MAME32...it doesn't see them...even though test mode shows NO SHORTS and the keys register.

!?!?! Gadzooks this is confusing

[BobA]

You are using a continuity tester on wires that are connected to the IPAC you will probably see different resistances because the circuits on the IPAC conduct.  The only thing that would indicate short would be a ZERO ohm reading or close to it on your Ohm meter.   The IPAC has good self diagnostics.

I think you are going around in circles trying to test in this manner.  

Test out the ipac board with a simple jumper to ground.  You can test each input to see that it works.  If something does not function then disconnect the wire connected to it and test again with a jumper.  Systematic checking will indicate what your actual problem is.

BobA

[OSCAR]

UPDATE:There is definately something "UP" With either my IPAC or the new Windows utility.

Using Ctrl ALT P and putting the Ipac into test mode, ALL MY BUTTONS register......however, when using the WinIPAC utility, I cannot assign any inputs at ALL to buttons 5-8 on players 3 and 4....press the button, and I press any keyboard button, and it wont register.

Also, on player 1 and 2 you can right mouse click on a button on the GUI and select a function like APPLICATION or POWER, as is detailed in Andy's writeup of the new release....but if you try that on player 3 or 4 inputs, no dice.  I'm not sure if its designed that way or just an oversight.

Anyhow, I'm going to try programming with the DOS version.

The annoying thing is that even with the jumper set to default MAME settings, I STILL can't use those buttons when using MAME32...it doesn't see them...even though test mode shows NO SHORTS and the keys register.

!?!?! Gadzooks this is confusing

This sounds like it's worthy of an email to Andy for help.  

[HeadRusch]

Oh yes, Andy's already asking questions and I'm trying to give him reasonable answers

Its just so damn odd.  The board shows no shorts, the TEST mode works great (all buttons registering!), and the stupid thing is pretty simple to wire up

"Player one.....here....Player two.......here".  I knew that college degree would pay off!

But the programming just doesn't work for me.....I even tried the DOS util, and its no go.  

I gotta tell ya..I *loathe* the idea of having to replace the IPAQ....although it will give me the opportunity to deal with the rats nest of wires.

[AlanS17]

When I first read this topic I thought you meant you had problems in the bedroom, but an understanding partner.  

[BeBoxer]

My little $5.00 voltmeter is set to read continuity.....for example, red lead on NC and black lead on ground and boom, the numbers take off (then start to drop as the batteries try to push as much as they can).
Then, touching NO....no flow.  Until I press the button, circuit is closed, and I get readings.  "Good Switch" I say.

I'm still confused. By "continutity", do you mean resistance? If so, your description doesn't make sense. The NC contact is "normally closed", meaning it is connected to ground when you are NOT pressing the button. Which means that you should measure zero ohms and zero volts, or very close to it, between NC and GND when you are not pressing the button.

You are wiring the inputs on your I-PAC to the NO contacts, right? Because if you have wired the inputs to the NC contacts, which are all connected to the GND without the buttons pressed, then you would basically have every input, every contact, everything in your CP wired up to ground. Which would explain why you are having problems. It wouldn't explain why anything works at all, at least not that I can figure out.

Either way, phrases like "no flow" and "good reading" don't really mean much. Please just state what you're measuring in volts or ohms as appropriate. Not to nag, it's just difficult to debug if we have to guess what you're actually seeing.

[HeadRusch]

Sorry...am testing volts...and 'odd things' are happening.....jury is out on whats up, I'm waiting on Andy to reply with suggestions.

Again...the built-in IPAC test mode shows no shorts at all and 100% functionality even on the keys that refuse to work when I try to program....either by DOS or by Windows.....