Joystick Ports Not Working

[XLR-VIII]

I recently purchased a Atari XEGS on eBay and it will boot up missile command, however I have no response from any controller/joystick I plug in. When I plug in the keyboard and start up the unit, it will boot up in basic and Im able to type in commands with no problem.

 

I checked all the solder joints and re-flowed all pins at the controller ports. I also checked for +5v and ground at the ports.

 

No sure how rare it problem is.... Any suggestions to what I should check next? Thanks in advance ??

[+mytek]

If it's only direction inputs that aren't working then it's probably a bad PIA (R6520) chip. Be simple to check... find a game that uses paddle controllers and if that works with a paddle, then it's likely that PIA chip is the problem.

[+Nezgar]

Since you mentioned you have the keyboard and can type in BASIC, enter this program, and see what/what doesn't change when trying all directions and buttons of both joysticks, and turning paddles.

 

10 ? STICK(0),STRIG(0),STICK(1),STRIG(1),PADDLE(0),PADDLE(1):GOTO 10
RUN

PTRIG checks not needed for testing since that shares joystick left/right on each port.

[XLR-VIII]

I tried super breakout and cant get it do anything... however it does show something when I press each fire button on the paddles. If I select 2 players and press the fire buttons each players score which is showing 0 will change color. Thats it...

 

If it's only direction inputs that aren't working then it's probably a bad PIA (R6520) chip. Be simple to check... find a game that uses paddle controllers and if that works with a paddle, then it's likely that PIA chip is the problem.

Edited August 19, 2018 by XLR-VIII

[XLR-VIII]

Both paddles turned fully left

15 1

228 228

 

Both paddles turned fully left and both buttons held down

3 1

228 228

 

 

Both paddles turned fully right

15 1

1 1

 

I noticed the value of the first digit changes depending on which fire button I press on each paddle

7 and 11

 

 

Since you mentioned you have the keyboard and can type in BASIC, enter this program, and see what/what doesn't change when trying all directions and buttons of both joysticks, and turning paddles.

 

 

10 ? STICK(0),STRIG(0),STICK(1),STRIG(1),PADDLE(0),PADDLE(1):GOTO 10
RUN

PTRIG checks not needed for testing since that shares joystick left/right on each port.

Edited August 19, 2018 by XLR-VIII

[+Nezgar]

Do you see a smooth increment/decrement of the PADDLE(x) numbers when slowly turning it ? (There will be a dead zone of a bout 1/3 of the total turning range)

 

Trigger on Paddle 0 / 1 should be equivalent to pressing left or right on the joystick (11 or 7) which is consistent with your tests.

 

Can you confirm if you can see all 9 direction codes (8 directions + center) with a Joystick?

 

Picture from https://www.atarimagazines.com/v5n1/derejoystick.html

[XLR-VIII]

Okay, I figured it out.. after your first post I then realized the unit was receiving inputs from both joystick ports. So then I thought... what about the (start,select,options,reset) buttons in the unit. I checked it with my multimeter and noticed (start) and (select) werent responding! I took some rubbing alcohol and cleaned out the two buttons. Voila! Everything is working great now!!! ?

 

 

I want to thank you and mytek for the help ??

 

And my POTS on my paddles are junk... when playing super break out I noticed they wiggle a little. On that BASIC test when I center a paddle it with move from 114 to around 120 and anything in between those two numbers ?

 

 

Do you see a smooth increment/decrement of the PADDLE(x) numbers when slowly turning it ? (There will be a dead zone of a bout 1/3 of the total turning range)

 

Trigger on Paddle 0 / 1 should be equivalent to pressing left or right on the joystick (11 or 7) which is consistent with your tests.

 

Can you confirm if you can see all 9 direction codes (8 directions + center) with a Joystick?

 

Picture from https://www.atarimagazines.com/v5n1/derejoystick.html

derejoystick1.jpg

Edited August 19, 2018 by XLR-VIII

[+Nezgar]

Good to hear it was a simple fix! The 'jittery' paddle pots are a common problem. You can try working some alcohol or electronics cleaner into the pots. Or, BEST sells new replacement pots too.. http://www.best-electronics-ca.com/cx30_paddle.htm

[+DrVenkman]

Deoxit has become my "go-to" for fixing jittery paddles. A single quick spray into the pot, work it back and forth vigorously for a couple minutes to let the active ingredients do their magic and dry, then play some 2600 Kaboom as a test.

[+David_P]

Deoxit has become my "go-to" for fixing jittery paddles. A single quick spray into the pot, work it back and forth vigorously for a couple minutes to let the active ingredients do their magic and dry, then play some 2600 Kaboom as a test.

 

"Are spending all night playing video games again?"

 

"No! I'm fixing collectable classic electronics equipment and doing detailed function tests!"