Option and select

[TXG/MNX]

I got still an issue with my XE all keys work except option and select. Anyone knows an easy way to fix this ?

 

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[Vyper68]

Sounds like the keyboard Mylar is starting to fail. Either source a new replacement one or try and repair the damaged tracks with some conductive paint.

You will need to determine if it is a single or double layer Mylar in your keyboard. If you have springs under your keys it should be a single layer Mylar. You can buy brand new reproduction parts for that one, not sure about the double layer.

[Mclaneinc]

Sounds like what happened to me, once the mylar was inspected you could see the tracks on the plastic had just vanished, Vyper above kindly sent me some conductive paint but I then found there were other tracks gone and the paint was very hard to get continuity from, took loads of layers. Thankfully Vyper also had a spare mylar for my model so some paypal was exchanged    He looked after me very well.

 

I spoke to one of the guys that was offering mylars on AA in an old thread and he had still got some stuff.

[StickJock]

It could be a broken trace, but I remember reading about issues with the console keys on the XEs.  IIRC, the console keys were especially susceptible to failing due to increased resistance on old keyboard membranes.  The concole keys go to the GTIA chip instead of the Pokey (via the 4051s) like the rest of the keyboard.  One fix was to gang additional resistors in parallel with the resistors on these lines on the PCB in order to lower the overall resistance of these buttons.

 

 

[TXG/MNX]

Okay thanx for the hint of the gtia, indid socket it because of a sophia install but did not test the keyboard after. I also installed antonia.
I will revert to the normal GTIA and cpu + mmu maybe I did cause an issue when old gtia was removed.


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[TXG/MNX]

It could be a broken trace, but I remember reading about issues with the console keys on the XEs.  IIRC, the console keys were especially susceptible to failing due to increased resistance on old keyboard membranes.  The concole keys go to the GTIA chip instead of the Pokey (via the 4051s) like the rest of the keyboard.  One fix was to gang additional resistors in parallel with the resistors on these lines on the PCB in order to lower the overall resistance of these buttons.
 
 

Do you have more info about that redistor mod?

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[StickJock]

14 minutes ago, TXG/MNX said:

Do you have more info about that redistor mod?
 

Search is your friend! ?

 

 

[+Nezgar]

Yes, you can delay replacing the entire XE mylar with the resistor trick in the thread that @StickJock linked to. I encountered one XE with this implemented previously, implemented it myself successfully in another, and added additional info & photos to that thread.

 

If you go through the verification steps I described in post #19 of the thread, and you can confirm with a multimeter you see some conductivity when the function keys are pressed, this resistor modification should work to improve the GTIA's ability to detect the keypresses.

[TXG/MNX]

Search is your friend! [emoji3]
 
 

Thanx this helps alot all my XEs just work without any issues so never seen this before

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[manterola]

Check for other sources of the problem (the schematics are you fiends), it might be a non working pin in the keyword connector, a dirty mylar edge, etc. 

Now, if a new double layer Mylar is needed, I got mine from the brewing academy and it has been working great. @MacRorie is the contact you need here in Atariage forums.

[TXG/MNX]

Check for other sources of the problem (the schematics are you fiends), it might be a non working pin in the keyword connector, a dirty mylar edge, etc. 
Now, if a new double layer Mylar is needed, I got mine from the brewing academy and it has been working great. [mention=16779]MacRorie[/mention] is the contact you need here in Atariage forums.

Yes will check tomorow I got a good starting point now [emoji41]

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[Mathy]

Hello guys

 

Since TXG/MNX is living in Europe, Duddie might be a cheaper source.  IIRC he reproduced and sold at least one type of XE mylar.

 

BTW PEEK(53279) should read the console keys.  I opened up my first 130XE so many times (partly because of the bad mylar) back in the days that I seem to have this number etched into my brain for ever.

 

Sincerely

 

Mathy

[TXG/MNX]

Just solved the issue my GTIA went bad, only select and option not working after replacing it all keys work.
So no resistor mod needed

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[StickJock]

It's possible that you had some corrosion built up on some of the GTIA's socket's pins that scraped off when you swapped chips.  The corrosion would increase the resistance on those pins.  You may want to try cleaning the socket and try your "bad" chip again.  Easy enough to test, and it just may save you a chip.