2600 jr Player 2 Paddle not Working

[rasch_C]

I am struggling 3 days to my deadline (Xmas) to get this 2600 jr. working. Everything works great on it, except the player 2 paddle pot does not respond. It reads the button fine, but not the pot. The paddles work great on my other systems (freshly rebuilt by myself), and I have tried another set of paddles on the jr with the same result (dead player 2 pot).

 

Joystick port pins and connections to the board are all fine, and there is continuity from the pins for the pots to their respective pins on the TIA. Tomorrow I'm gonna verify player 3 & 4 paddle inputs work. I'm gonna sleep on it and look into again in the morning with a fresh mind, but any thoughts would be greatly appreciated. I'm giving this as a gift.

 

Thanks In Advance

[karokoenig]

Bumping this up on top of the "New Content" list. That's all I can do to help, really... If the plugs and solder points are ok, it sounds like a more serious problem. If you need your gift tomorrow, it may be a tad late to solve it. Why not give away your own working console for now and deal with the problematic one later?

[BigO]

There could be a problem with the capacitor on that player 2 input, or the resistor in that line (I think some models didn't have that resistor) or with the I/O pin on the TIA.

Since you said there's continuity through to the TIA pin, it's not likely the resistor.

 

In a time crunch like you have, I'd hope for it to be the capacitor.

Swap out the capacitor on the non-functional paddle input line with a known working one from one of the other paddle input lines to see if the problem follows the capacitor.

http://atariage.com/2600/archives/schematics/Schematic_2600_Low.html

 

Of course, if the problem goes away completely you'll know there was a bad solder joint on the cap.

Edited December 23, 2013 by BigO

[rasch_C]

All good info. I only have a Heavy-6, Light-6, and Video Arcade II, personally. So, giving them one of those is out, especially with their tight space situation.

 

I did check the resitor (1800 ohm rated if memory serves), and that checked out OK last night. After sleeping on it, and with your suggestion, BigO, I think I'll warmup the ol' iron tonight when I get done with work and swap the cap and see if the problem follows. Hopefully, that'll be what the problem is and we'll be all set I'll keep everyone updated. Thanks.

[rasch_C]

In short; the problem was non-existent after all.

 

In the time rush that I've been on for the last 2 months, I didn't properly test the unit when I got it in. I only bored up breakout to the screen selection menu (didn't) actually play that particular game. And games 3 & 4 actually use a paddle from either set on the screen at the same time, not from the same set.

 

I backed up a little bit and discovered there was no problem after I swapped caps and still had the same "experience".

 

Thanks again everyone for the always reliable help on here when needed! Gonna be on our way to family Xmas shortly to deliver said gift. I think they'll love it.

 

Hope everyone's holiday is going great!!