Atari 800 vintage Joystick port1 - right move not working

[80sAtariboy]

Hello All

I was hoping if someone had any advice on old Atari's 8 bits. I recently purchased a 1979, Atari 800, Vintage and it works fine except for one thing. Joystick port 1 will not register a right move. Left, up and down work fine. I replaced the whole Joystick Jack incase it was a broken pin but still the same problem. I know Pin 4 is right on the 5 pin row. The traces seem fine but I was wondering if there is a failed capacitor. I see a whole row of capacitors behind all the Joystick ports 1-4. 

Does anyone have any advice please what else I can do?  I am an amateur and do not have any meters or service manuals. thanks

[ivop]

I strongly advise getting a multimeter. They can be had for only a few dollars. Not the best quality, but enough to measure resistance and continuity. That way, you can check if the pin's signal even reaches the PIA chip.

 

[Rybags]

I'd lift & reseat the PIA.

If that makes no difference then I'd suspect most likely a damaged PIA or severed trace.

[TGB1718]

Are you sure it's the joystick port and not the stick itself ?

 

Simple BASIC to test, put the Joystick into port 2

 

10 ? STICK(1)

20 GOTO 10

 

and move the stick to see the numbers change should be 7 for right, 6 for Up/Right, 5 for Down/Right

[80sAtariboy]

4 hours ago, Rybags said:

I'd lift & reseat the PIA.

If that makes no difference then I'd suspect most likely a damaged PIA or severed trace.

Thanks to all who gave advice. I replaced the PIA from a working 800xl and installed it in my 800U. Now port 1 works as it should with the right movement registering. I actually put the PIA from the 800U into the 800xl and got the same fault - no right movement registering. So it was a faulty chip in my 800U when I purchased. I will order a replacement in anycase. 

 

Thanks to All for the advice. Nice to know there is a wealth of knowledge from Atari fans all over the World! 

[80sAtariboy]

Just now, TGB1718 said:

Are you sure it's the joystick port and not the stick itself ?

 

Simple BASIC to test, put the Joystick into port 2

 

10 ? STICK(1)

20 GOTO 10

 

and move the stick to see the numbers change should be 7 for right, 6 for Up/Right, 5 for Down/Right

thanks for the advice. Really handy to know. My PIA is faulty in the 800U and I replaced it with a working one from an Atari 800XL for now, till I get a replacement. 

[TGB1718]

12 minutes ago, 80sAtariboy said:

thanks for the advice

Nice to know it's resolved and an easy fix