Controller Port Problem/Unwanted Autofire

[Controller Port Problem/Unwanted Autofire]

3 hours ago, DrVenkman said:

 

RIOT handles directional signals on the controller ports; TIA handles the FIRE button signals, run through some resistors. There are 470pF capacitors on each joystick FIRE button as well. If one or both of those are shorted, that might be the cause of your issue. Or you might actually have a bad TIA chip. Check capacitors C33 and C34 for the Left and Right ports, respectively, then resistors R34 and R35 for the resistors on the same trigger lines. These lines lead to TIA pins 36 and 35, respectively.

 

Good luck.  

So I tried combat with player 2's controller port, and the same effect occurs (just with player 2 now).  The problem is definitely with the Atari and not my controllers.  Should I replace my TIA chip?  What exactly do I check R34, R35, C33, and C34 for?  I have a multimeter.

[Controller Port Problem/Unwanted Autofire]

3 hours ago, SmittyB said:

What sort of controllers are you using; official 7800 ones?

I have tried it with the original 7800 controllers and with Sega Genesis controllers.  Same effect occurs.

[Atari 7800 Controller Problems]

2 hours ago, ChildOfCv said:

Are they still "held down" even without the controller plugged in?

 

Also check that the wire that connects between both switches has +5V on it.  If not, then it's probable that pin 6 is no longer connected.  Reflowing the plug connections to the motherboard will probably fix it.

Only when the controller is plugged in. Which wire are you talking about? When you say reflow, does that mean touching the solder with the soldering iron?

[Controller Port Problem/Unwanted Autofire]

1 hour ago, boggis the cat said:

Does it do this with no controllers attached?

No. Just opens up the intro screen for the game.

[Atari 7800 Controller Problems]

I posted this to the general Atari 7800 forum, but maybe this is a better spot for it.

 

My Atari 7800, out of nowhere, stopped working with controllers.  When playing any game, the game acts like both buttons are being held down.  I took off the casing and shield to inspect the circuit board, but nothing seems out of the ordinary.

 

Does anyone have any advice on how to troubleshoot/repair?  I'm not really wanting to buy a replacement console.

[Controller Port Problem/Unwanted Autofire]

No matter what game I try or which controller I use, my 7800 will now think I am rapidly pressing both of the fire buttons.  Is something wrong with the controller port?  I'm hoping whatever it is, it will be an easy fix, but I dread that I might need to crack it open and operate on the circuit board.

[Subtle Label Variations]

I came across two different label variations of Xevious, originally thinking that one must be a reproduction.  I read about the different label styles at http://www.atariprotos.com/other/labelvar/7800/7800labelvar.htm but the site says nothing about subtle variations of the same style.  At the bottom of the two labels one says "Printed in Hong Kong", and the other says "Printed in Taiwan".  I believe the Taiwan style is the one that is uploaded in the label archives on Atariage.  Does anyone have any information on Atari 7800 label variations?