Atari 2600 4 switch, Down not working on controller?

[Mr. Postman]

At first I thought it was my controller, but I've tested multiple controllers and the same result. I've attempted to clean the port with a toothbrush and 91% alcoholic, but no-go. The board (revision 5) looks to be in excellent shape, I don't see any cold solder joints, scratched traces or bad resistors by eyeballing.

 

Has anyone else had a similar issue?

 

As always, any and all advice is greatly appreciated. Thanks everyone.

[SignGuy81]

Take a multimeter and check for continuity between the pins(that plug in to the controller plug) and the back side of the connector on the board. It isn't a solid pin that goes thru and down, and sometimes on the back side the pins slide out of the corresponding one from the other side. You set the meter on ohms and if you have OL or high resistance on one that will be the problem. You should have close to 0 ohms on the good ones.

 

Could be other things to but want to check that first. But also it could be the solder joints where the pins meet the board so go ahead and look for that too.

 

EDIT:

 

So you don't make the same mistake I have before when you are testing with the test leads be careful not to press the lead of the pins on the back toward the front because this can cause it to make contact while you are checking it, everything look good then try a game and be like WTF

Edited June 2, 2017 by SignGuy81

[Mr. Postman]

Thanks, I'll check with a multimeter and report back.

[Mr. Postman]

Thanks, with the multimeter it's a bad resistor. Thank you so much.

[SignGuy81]

Thanks, with the multimeter it's a bad resistor. Thank you so much.

 

It shouldn't be a bad resistor.

 

NM I think you mean it will look like a bad resistor(open) on the multimeter, and not that you found one correct?

Edited June 2, 2017 by SignGuy81

[SignGuy81]

The reason I was asking is the direction inputs run straight into the RIOT(no pull-up or pull-down resistors externally) and a resistor will not be your problem.

[SignGuy81]

To save you some time it is pin two you are looking for, here is pinout https://atariage.com/2600/archives/schematics/Schematic_2600_Accessories_High.html

[Mr. Postman]

My pin 2 resistor reads zero. The other 3 read read 2.5~ish

 

According to a color band calculator it's a 1k 10%, no idea about the wattage.

[Mr. Postman]

C228 reads zero.

[SignGuy81]

Those aren't resistors they are caps, do not worry about those

[SignGuy81]

You just have a bad controller port probably. DB-9 connector needs fixing or replacing probably.

Edited June 2, 2017 by SignGuy81

[SignGuy81]

you need to do the test like I mentioned. Test just the pins from the outside to the inside. Nothing else.

[Mr. Postman]

I appreciate the help. The pins on the connector read fine. Those are resistors, not caps. I suppose I'll test all the DB-9 connections again but none were open.

[FMTownsMarty]

you need to do the test like I mentioned. Test just the pins from the outside to the inside. Nothing else.

 

Those aren't resistors they are caps, do not worry about those

 

Nothing like misinformation and condescension in the same help thread....

[SignGuy81]

I appreciate the help. The pins on the connector read fine. Those are resistors, not caps. I suppose I'll test all the DB-9 connections again but none were open.

 

Can someone please back me up here? Trust me they are caps. Yes they look like resistors I'll give you that but they are caps. If you did do the check like I asked and pin 2 from front to back is good, and no broken solder joints then the problem would be the RIOT chip. But I would double check those pins again.

[SignGuy81]

 

 

Nothing like misinformation and condescension in the same help thread....

Condescending maybe.

 

EDIT:

 

And the reason I asked him to do just the test I asked with his meter and nothing else was because he was going down the wrong path, checking CAPS(not resistors, that aren't even part of the directional inputs). And I told him NOTHING ELSE because there is nothing else there to check with the meter other than what I told him because it is a straight line to the RIOT. I'm not trying to be a jerk I'm trying to help somebody.

 

Nothing like a newbie coming in first post who thinks he is a know(not talking about the OP) it all calling others work misinformation.

Edited June 2, 2017 by SignGuy81

[Mr. Postman]

The db-9 tests fine on every connection. I reflowed the joints on the c228 and it now reads 47k (instead of zero) while the others read 2.5k. Something is wrong with that component.

Edited June 2, 2017 by Mr. Postman

[Mr. Postman]

It doesn't look any different than a resistor, band coded and everything.

[FMTownsMarty]

Condescending maybe.

 

EDIT:

 

And the reason I asked him to do just the test I asked with his meter and nothing else was because he was going down the wrong path, checking CAPS(not resistors, that aren't even part of the directional inputs). And I told him NOTHING ELSE because there is nothing else there to check with the meter other than what I told him because it is a straight line to the RIOT. I'm not trying to be a jerk I'm trying to help somebody.

 

Nothing like a newbie coming in first post who thinks he is a know(not talking about the OP) it all calling others work misinformation.

At what point did I act like a know it all? You're the one acting like a jackass in a thread where someone asked for help. If the DB9 tests fine and the RIOT tests fine (wouldn't a bad RIOT produce funky video or have problems other than 1 direction?) and there's only one component between them.....

Edited June 2, 2017 by FMTownsMarty

[SignGuy81]

At what point did I act like a know it all? You're the one acting like a jackass in a thread where someone asked for help. If the DB9 tests fine and the RIOT tests fine (wouldn't a bad RIOT produce funky video or have problems other than 1 direction?) and there's only one component between them.....

 

 

By telling somebody who has a degree in electronics, plus has been repairing electronics for years that they are providing misinformation when you are clueless about the topic. And there is no component between the two other than the trace on the board. Like I said those caps have nothing to do with it. The C before the number stands for capacitor by the way. But to put a rest to this here if you still don't believe me https://wiktel.com/standards/capa.htm and you are the one providing misinformation by making him think he is right when I'm only trying to help him.

[SignGuy81]

Now. Back to trying to be helpful to the person who needed help while I was rudely interrupted, I should point out the fact that yes I did overlook something completely and that was whether or not you have tried another controller. The problem could be in that.

 

EDIT:

 

just went back up and read sorry my mind got sidetracked by all that but now know yes you already tried other controllers.

Edited June 2, 2017 by SignGuy81

[SignGuy81]

Check the solder joint at pin 14 of the RIOT chip as well, that is where pin 2 of the first controller port goes.

[SignGuy81]

To the OP. Another check you can do is to put a game in, and with it on jump a wire from ground to the back side of the controller port on pin two. Looking at the first port from the backside it will be the top row of pins, and the 2nd one from your right looking at it from the back. If you jump that pin with ground and whatever moves down or whatever down does on that game happens then it is the DB-9 connector. Probably easier to test this way than trying to line up your test leads with front and back of the connector.

 

Just be careful not to accidentally tap the grounded wire to anything else.

Edited June 2, 2017 by SignGuy81

[Mr. Postman]

May I ask what that cap is? 5-band --- Brown black red silver silver ?

Edited June 2, 2017 by Mr. Postman

[Mr. Postman]

Up to ground works, down to ground doesn't.