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General Category => Technical Support => Topic started by: anyf33 on 18:33, 04 September 16

Title: Keyboard problem at 6128
Post by: anyf33 on 18:33, 04 September 16
This one of my 6128's . If i  connect joyctick(not working) or not the keyboard have the same results.
also membrane tested: i use another full working keyboard from another cpc and i have the same results.
[youtube]https://youtu.be/a2g2wHhFPJw

[/youtube]
Title: Re: Keyboard problem at 6128
Post by: Token on 19:29, 04 September 16
It could be the AY. (often reported)
Title: Re: Keyboard problem at 6128
Post by: VincentGR on 20:16, 04 September 16
If the contacts on keyboard's socket are clean and the same pattern appears by pressing a key or without the keyboard attached, then is definitely the AY.
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 20:46, 04 September 16
without the keyboard nothing typed!
when i press a key like enter or any of the other keys space or any letter or number nothing happens
the only keys that work showed in the video
works ! ha ha the type all of these letters
but this is for anytime i press it
and with any keyboard!
the very best is the key Μ that types capitals and enter, pressing again lower cases and enter
Title: Re: Keyboard problem at 6128
Post by: Bryce on 22:04, 04 September 16
AY needs to be replaced.

Bryce.
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 08:04, 28 September 16
urgent!!
 :o :o :o :o
I change the AY and the problem still exist!!!
i think that sound's like a joke but it is not!
In the first photo it is the old chip taken from the cpc
the three other's is from the cpc with this crazy keybord!!

Title: Re: Keyboard problem at 6128
Post by: Audronic on 08:26, 28 September 16
@anyf33 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1636)

If you connect the Joystick can you get any characters to appear on the screen ? by pressing fire or /up/down/left/right

If Not then you could change the 74ls145.
Or if that did not work then the 8255.
Please use good quality sockets.

Good luck    Ray
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 08:35, 28 September 16
of course the joystick dont work!

with the new ay the problem it is just the same .the same buttons the same kjgodfsgndonfsdm
but when i press several buttons i see some keyboard commands (like <- or X) pressing specific button from keyboard (something like fdshnu9-<X) NOTE the "fdshnu9-<X" it is NOT what i get i type it now from my mind just to show you )
Title: Re: Keyboard problem at 6128
Post by: Bryce on 10:27, 28 September 16
Yup, the 74LS145 is the next most likely culprit.

Bryce.
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 23:26, 05 October 16
N :(  because of devilmarkus
So i change 74LS1455
74LS145
and the problem still exists BUT Changed!
now L,M and others dont work and some numbers work like 4 and give me something like [-97532and down arrow
of course joystick dont work
the chip is labeled N74145 B see pictures
please help!
Title: Re: Keyboard problem at 6128
Post by: Bryce on 10:02, 06 October 16
N :(  because of devilmarkus
So i change 74LS1455
74LS145
and the problem still exists BUT Changed!
now L,M and others dont work and some numbers work like 4 and give me something like [-97532and down arrow
of course joystick dont work
the chip is labeled N74145 B see pictures
please help!

What museum did you find that chip in?? It's from 1976, the wrong type and unlikely to work properly. It should be a 74LS145.

Bryce.
Title: Re: Keyboard problem at 6128
Post by: Audronic on 06:28, 28 October 16
@anyf33 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1636)


Hows the project going.
Fixed or still faulty. ?


Ray
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 07:49, 28 October 16
@anyf33 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1636)
Thsnk you for your interest! My friend change the chip but i can test it until monday.


Hows the project going.
Fixed or still faulty. ?


Ray
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 01:36, 01 November 16
What museum did you find that chip in?? It's from 1976, the wrong type and unlikely to work properly. It should be a 74LS145.

Bryce.
@bryce i have the same problem. So i changed the 74LS145 From a WORKING 464 to be sure it is the right one. but.... i have the same problem keys dont work. only some keys that they type many characters (you can see the video  i posted at page 1 BEFORE I Change both ay  and 74LS145. total 2 chips but the problem still the same. if you remember joystick dont work. also another keyboard also dont work!!!!!!!! please help
Title: Re: Keyboard problem at 6128
Post by: Audronic on 01:47, 01 November 16
@anyf33 (http://www.cpcwiki.eu/forum/index.php?action=profile;u=1636)


Ray
Title: Re: Keyboard problem at 6128
Post by: Bryce on 13:07, 01 November 16
@bryce i have the same problem. So i changed the 74LS145 From a WORKING 464 to be sure it is the right one. but.... i have the same problem keys dont work. only some keys that they type many characters (you can see the video  i posted at page 1 BEFORE I Change both ay  and 74LS145. total 2 chips but the problem still the same. if you remember joystick dont work. also another keyboard also dont work!!!!!!!! please help

As Audronic says, then it really only can be the 8255, however I still have problems believing this because the 8255 is pretty much bullet-proof.

Bryce.
Title: Re: Keyboard problem at 6128
Post by: anyf33 on 03:06, 12 March 17
 :D :D :D :D
After many months i buy a toshiba one and change it. And finally it works!!
i is like new i dont believe it will be fixed!!
many thanks to all