Upper fire button not working

[NML32]

Just noticed today that the upper fire buttons aren't working on my 4 port 5200.

I found out when trying to play Xevious and Qix.

 

Any ideas what the problem might be?

 

Thanks,

Mark

[zylon]

Just noticed today that the upper fire buttons aren't working on my 4 port 5200.

I found out when trying to play Xevious and Qix.

 

Any ideas what the problem might be?

 

Thanks,

Mark

I would open a controller and see if it works by touching the contacts for the button with something metal.

Could be a problem with the controller port or the system. Try playing a game on 2 player setting. See if the button works for player 2. If it does, your port may be bad. If it still doesn't, POKEY chip may have started to fail.

[NML32]

Not working even as second player. Can the Pokey chip be replaced?

[zylon]

Not working even as second player. Can the Pokey chip be replaced?

Yes. It's this one. No guarantees, but that one would cause that issue.

[0078265317]

The controllers are famous for breaking. Try fixing the controller first. Replace the mylar flex circuit and see.

[NML32]

The controllers are famous for breaking. Try fixing the controller first. Replace the mylar flex circuit and see.

 

I found my old 5200 that I had from a long time ago that I put away when I bought this one that was modded with a SVideo upgrade.

 

The joysticks work fine on that board. I even swapped the pokey chips and that did not work same issue.

 

I might just move the video mod over to the working board, both are 4 port systems.

[zylon]

The controllers are famous for breaking. Try fixing the controller first. Replace the mylar flex circuit and see.

 

I found my old 5200 that I had from a long time ago that I put away when I bought this one that was modded with a SVideo upgrade.

 

The joysticks work fine on that board. I even swapped the pokey chips and that did not work same issue.

 

I might just move the video mod over to the working board, both are 4 port systems.

Good! Glad you got one working. That does lead me to believe a cap or trace on the board may be bad then. Remote diagnosis isn't an exact science.

[bohoki]

the controller ports pins are easily broken is yours missing any?

 

like the one second from the right bottom

[NML32]

I swapped mother boards and moved the video mod over to the working 5200. So I at least I have one working 5200.

[zylon]

In consulting my service manual on 5200's, it's showing that the GTIA chip handles the fire buttons on 5200's. It's worth looking into.

[NML32]

In consulting my service manual on 5200's, it's showing that the GTIA chip handles the fire buttons on 5200's. It's worth looking into.

 

Thanks for the info. I tried looking up the chip but couldn't find any photos or location where the chip would be located on the board.

 

Which one on the board is the GTIA?

 

Thanks,

Mark

[zylon]

BRB...

 

Ok, back now. GTIA is pointed out in the pic. I believe that one is dying on the board pictured since it only displayed B&W. I've been using it for parts since most of the ports were bad also.

Edited May 28, 2011 by zylon

[NML32]

BRB...

 

Ok, back now. GTIA is pointed out in the pic. I believe that one is dying on the board pictured since it only displayed B&W. I've been using it for parts since most of the ports were bad also.

 

Thanks for the picture.