600xl and some dead keys..

[Mikeee76]

Hello everyone!
it's my first post here (been lurking here for a while although),
My name is Michael and I've bought recently two 600xl.
(Owned one 600xl (later an 800xl) as a child).

One of them works perfectly, the other one has some keyboard issues...
Some keys won't work ( 5,8, T, I, G, K, B, M ,to be precise).

According to this thread [http://atariage.com/forums/topic/105170-600800xl-keyboard-variants/]
it's the "type 3" keyboard (by AWC, with springs and mechanical switches).
I've already detached it from the mainboard and the connector/band seems to be OK.
Since it has no mylar I also removed the cap from a "5" key (as an example) to see if the switch works and yes, it does.

My question:
What to do next?, do you have any ideas?
Thanks.

[manterola]

All those keys are part of the line 12.

That is connected to IN2

So the most likely problem is a trace broken in the keyboard PCB. Or in the cable. Check the diagrams attached.

Welcome to the forums

[xrbrevin]

Hi,

the ribbon cable on 600xl keyboards are notorious for being hit n miss. Give it a wiggle and see if the keys work intermittently, it may help detect the fault..

when i dealt with mine, i discovered several pins in the original flat ribbon socket (the motherboard one) had snapped inside the black plastic housing. so i soldered in a 1x24-pin header onto the motherboard and made a ribbon cable to suit.

i think the original ribbon cable and the resistor board are a bit too bulky and mustve got stress fractured.

the repair was a bit of a repetitive faff but it solved the problem with a long term durable repair. i also found it ran fine without the intermediate resistor board.

[JR>]

. i also found it ran fine without the intermediate resistor board.

I have 3 600XLs and none of them have the resistor board. I wonder how common it really was?

[Mikeee76]

As Manterola mentioned, it was indeed a broken line (Line12) in the keyboard pcb.
Someone tried to fix it in the past (the path was already soldered).
The keyboard works now.
Thank you very much!