Atari 2600 silver switch wiring

[rawbe]

Is it possible to solder onto a non working Atari 2600 board and use the switches? The silver switches have 6 pins and the black sliding switches have 3 pins. I tried hooking into the B/W to Color switch which has 6 pins. I tried different variations going to my PI GPIO and i can’t get the signal to turn off. I am not sure if it can be done or if it’s a wiring problem.

Please help! Thanks!
Robbie


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[PL1]

Is it possible to solder onto a non working Atari 2600 board and use the switches? The silver switches have 6 pins and the black sliding switches have 3 pins. I tried hooking into the B/W to Color switch which has 6 pins. I tried different variations going to my PI GPIO and i can’t get the signal to turn off. I am not sure if it can be done or if it’s a wiring problem.

The switches are DPDT (6 pin) or SPDT (3 pin) switches.
- Useful switch repair info at https://vintagegamingandmore.com/atari-switch-repair/.

The PCB trace layout could be the problem if you hook to the wrong contacts.
- The traces make the 6 pin DPDT switch work like the 2 pin SPST switch shown in the schematic.
- This PCB pic shows two switches with six pins each.  One switch to the left of the screw hole, one to the right.

- Common contacts in the center are tied together and to both contacts on one side. (group of 4 contacts -- top 4 of left switch, bottom 4 of right switch)
- Contacts on the other side are tied together. (group of 2 contacts)
- You need to figure out which group goes to ground and which group goes to the 6532 in the schematic.
- Connect the ground group to ground on your RasPi and the 6532 group to the GPIO.

Schematic from Atari Age:


The 3 pin switch could have a similar configuration where the center pin (common) is tied to the contact on one side, making it work like a SPST.


Scott

[rawbe]

Scott-
Thank you for helping! Are you suggesting something like this?

[PL1]

Are you suggesting something like this?

Second try is much closer.   
- Not sure which is ground and which is input. (see test procedure below)

There are two DPDT switches on the other side of the PCB. (orange rectangles with 6 pins)

Contacts are labeled for the left switch.
- Purple group has conductive traces between A1, A2, COM1, and COM2.
-- Solder one wire to any of the four purple group contacts. (all four are connected by the traces)
- Red group has a conductive trace between B1 and B2.
-- Solder a second wire to either of the two red group contacts. (both are connected by the traces)
- Connect one of the wires to RasPi ground and connect the other to the GPIO input.

How to tell which groups are ground:
1. Ensure no power is applied to the PCB . . . unless you want to fry your multimeter.   
2. Set your multimeter to continuity or ohms.
3. Set the switches so the internal contacts are on the purple and yellow groups.
*** Note that one switch will be open in the up position and the other will be open in the down position. ***
4. Verify that you have no continuity between purple group and red group. (left switch is in the open position/up)
5. Verify that you have no continuity between blue group and yellow group. (right switch is in the open position/down)
6. One of these four pairs of groups will have continuity (connection) through the PCB's ground.
Touch one multimeter lead to one group and the other lead to the other group.
Whichever pair gives you a beep (or <2 ohms) are your two ground groups.   
  - Purple + Blue
  - Purple + Yellow
  - Red + Blue
  - Red + Yellow


Scott

[rawbe]

Scott,

Thank you for spending time to reply and helping me. I have it working! Thank you!!

Robbie

[PL1]

Glad to assist.   


Scott