The Mr. Video Posted July 13, 2017 Share Posted July 13, 2017 Hi, today I got my 600XL to work but now I have another problem, the keyboard is broken. sometimes it just doesn't do anything, other times the A key sticks. The only thing that works all the time are the side-silver keys (except the help key), any help would be nice. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 13, 2017 Share Posted July 13, 2017 Possibly bad POKEY chip. POKEY controls all the keys on the keyboard (including Help) except Start, Select, Option and System Reset. Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 13, 2017 Author Share Posted July 13, 2017 I replaced the POKEY chip and it made no difference. Quote Link to comment Share on other sites More sharing options...
russg Posted July 13, 2017 Share Posted July 13, 2017 Hi, today I got my 600XL to work but now I have another problem, the keyboard is broken. sometimes it just doesn't do anything, other times the A key sticks. The only thing that works all the time are the side-silver keys (except the help key), any help would be nice. There are two CO4051 16 pin chips near the keyboard socket. If you can swap them maybe that would work. Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 13, 2017 Author Share Posted July 13, 2017 I just noticed there's a leg on the POKEY chip not in its socket, I'll try re-seating it. Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 13, 2017 Author Share Posted July 13, 2017 Reseating the POKEY chip didn't work, but I did take a closer look at the connecter and noticed that 2 of the connections on the far ends of the cable look burnt. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted July 14, 2017 Share Posted July 14, 2017 There's supposed to be a daughterboard with an array of current limiting resistors pushed into the motherboard keyboard edge connector. I take it this is missing? In any case, the traces require repair with conductive silver paint. Quote Link to comment Share on other sites More sharing options...
russg Posted July 14, 2017 Share Posted July 14, 2017 There are two CO4051 16 pin chips near the keyboard socket. If you can swap them maybe that would work. They are CD4051 RCA. Best has them for .69 cents or so, $20 minimum order. Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 14, 2017 Share Posted July 14, 2017 There's supposed to be a daughterboard with an array of current limiting resistors pushed into the motherboard keyboard edge connector. I take it this is missing? In any case, the traces require repair with conductive silver paint. I have yet to find a 600xl with that daughter board and many of my keyboards have that oxidized look. Start testing continuity. 2 Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted July 14, 2017 Share Posted July 14, 2017 I think many 600XL keyboards were swapped out and the resistor board kept with the outgoing one. Just had one through my hands with a missing keyboard adapter and... the traces were heavily burned and required repair. Pretty certain it was not the original keyboard. Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 14, 2017 Share Posted July 14, 2017 My 800XL's look just like that. just saying. Seems our experiences are different. I have one NIB 600XL i'll open and check. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted July 14, 2017 Share Posted July 14, 2017 Yep: 800XLs have the resistors on the motherboard, but that certainly doesn't prevent burned traces. I may be wrong, but I think someone pointed out a while ago that the current limiting resistors Atari used are actually the wrong values? Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 14, 2017 Author Share Posted July 14, 2017 There are two CO4051 16 pin chips near the keyboard socket. If you can swap them maybe that would work.Just replaced those and that didn't work. Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 15, 2017 Share Posted July 15, 2017 disassmble the keyboard and see if the mylar works by itself. Quote Link to comment Share on other sites More sharing options...
russg Posted July 15, 2017 Share Posted July 15, 2017 Just replaced those and that didn't work. can you swap the POKEY chip? Quote Link to comment Share on other sites More sharing options...
russg Posted July 15, 2017 Share Posted July 15, 2017 can you swap the POKEY chip? I neglected the first posts about replacing POKEY, sorry. Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 15, 2017 Share Posted July 15, 2017 Seems like an awful lot of soldering and chip swapping going on for a keyboard that "sometimes" produces a stuck A. Remove the billion tiny screws from the metal plate covering the keyboard mylar. Wash all the contacts on the mylar and the insert. Let dry. Plug into computer and test the keys before reassembling the keyboard. I've had a few keyboards that had liquid stuck in them or the white square keys were stuck down and messing up the signals. And make sure the keyboard is plugged into the connector good. Continuity check the heck out of it from the traces on the mylar to the solder joint of the socket. Its certainly possible pokey or other components have failed. But I like to rule out the keyboard first. Helps if you have another one to test with. Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted July 15, 2017 Share Posted July 15, 2017 Its certainly possible pokey or other components have failed. But I like to rule out the keyboard first. Helps if you have another one to test with. As someone (Jon?) wrote earlier - you can easily rule stuff in or out by testing continuity of the Mylar with a multimeter. Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 15, 2017 Author Share Posted July 15, 2017 disassmble the keyboard and see if the mylar works by itself.I just took apart the keyboard and tested the bare mylar and everything works fine now, I even tried pressing a key and it works. Perhaps the backing was screwed to tight? Quote Link to comment Share on other sites More sharing options...
The Mr. Video Posted July 15, 2017 Author Share Posted July 15, 2017 (edited) Alright I screwed the backing on and everything works fine now, thanks for the help. Edited July 15, 2017 by The Mr. Video 1 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted July 15, 2017 Share Posted July 15, 2017 It's possible, but maybe more than one key was stuck down. If everything works now assembled then you should be good to go. The white plastic keys crack in the corners at times and get stuck down or don't hold the key cap correctly. Springs can also get messed up but not as likely. It works. Enjoy it. Quote Link to comment Share on other sites More sharing options...
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