Sega Genesis 3 Button Controller: Unresponsive Up button

[TheMerc]

So, I've run into the mother of console humdingers. I have a Sega Genesis with a controller that has the up on the dpad not respond at all. I've tested the system with an aftermarket contoller, which works fine. Here's the kicker tho: to be sure, I plugged the faulty controller into my Atari 2600, (I dont have another Genesis to test with) and the controller works fine. What's wrong? Should I replace the controller ports on the system? Or is the controller the culprit?

[Andy-Antsinpants]

Please check your controller's plug and the sockets on your console for any faults. I think the GameSX wiki has a pin assignment diagram of the plug, so you are able to see which pin you should be looking for.

[eidis]

 Hi TheMerc !

Open your console and check for broken traces where the controller socket is soldered. This is one weak spot which can fail with time. Another reason for such behavior could be a bad cable. The D-pad is directly wired to the gamepads connector and those signal lines can be tested with a multimeter for continuity.

Keep the scene alive !
Eidis

[Segasonicfan]

Atari and Genesis have different protocols for handling the controller IC.  I wouldn't open the system, as I seriously doubt that is the fault.  I would:

1) consider replacing the controller (they are about $5) or
2) check the cable wire for bad connections
3) replace the logic IC in the controller (its standard 74 logic see GameSX wiki)

Also, just try another controller on the system to rule that out.

[eidis]

 Hi Segasonicfan !

Please look at the attached picture. This is a SEGA Mega Drive Model 2. There are clear signs that some connector pins had lost contact with the poorly made PCB, especially the two upper right pins.

Keep the scene alive !
Eidis