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General Category => Technical Support - General => Topic started by: CrookieMonster on 15:24, 04 December 19

Title: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 15:24, 04 December 19
I'm having yet another issue trying to bring my 464 Plus back to life.


I now have a cartridge with BASIC (thanks tjohnson for all of your help) but I'm now finding that a few of the keys on the keyboard are not working (from y to p, Return and some others.


Is there an easy method of working with keyboards to fix this? It's only affecting the right hand side of the keyboard.

Title: Re: Only half a 464 Plus keyboard is working
Post by: Bryce on 15:32, 04 December 19
First step would be to open it and clean the membrane. If that doesn't fix it, you need to work out whether it's a damaged membrane, dodgy AY chip or dodgy ASIC.

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: Skunkfish on 15:34, 04 December 19

@CrookieMonster (http://www.cpcwiki.eu/forum/index.php?action=profile;u=340)
I managed to resolve a longstanding issue with this on my 6128 Plus by cleaning the keyboard connector on the board with a piece of card as per 00WReX's suggestion in the thread linked below (thanks 00WReX by the way, I forgot to thank you in the other thread!)
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amstrad-6128-plus-keyboard-problem/msg177000/#msg177000
Title: Re: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 15:45, 04 December 19
Thanks both. I'll give this a go. I've also noticed that the controller doesn't work on the 464 Plus but does work on a GX4000: does it sound like a more widespread issue?
Title: Re: Only half a 464 Plus keyboard is working
Post by: Bryce on 15:50, 04 December 19
If the Joystick or controller doesn't work, then it's more likely that the AY chip is damaged. Does it play any sound?

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: mr_lou on 16:03, 04 December 19
Quote from: Skunkfish on 15:34, 04 December 19
@CrookieMonster (http://www.cpcwiki.eu/forum/index.php?action=profile;u=340)
I managed to resolve a longstanding issue with this on my 6128 Plus by cleaning the keyboard connector on the board with a piece of card as per 00WReX's suggestion in the thread linked below (thanks 00WReX by the way, I forgot to thank you in the other thread!)
http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amstrad-6128-plus-keyboard-problem/msg177000/#msg177000 (http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/amstrad-6128-plus-keyboard-problem/msg177000/#msg177000)

Interesting. Have to try this on my CPCplus too.
Some keys wasn't working a while back, so I replaced the membrane with a new one. This worked, but not for long. The same keys are acting up again every now and then. Maybe this cardboard method will work.
Title: Re: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 16:35, 04 December 19
Yes, it does play sound.


Quote from: Bryce on 15:50, 04 December 19
If the Joystick or controller doesn't work, then it's more likely that the AY chip is damaged. Does it play any sound?

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: Bryce on 08:43, 05 December 19
Ok. But the AY could still be the problem. Can you tell us exactly what keys don't work?

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 10:32, 05 December 19
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225) Its uiop jkl return and the | key. I don't think the function keys work and the up and right arrow keys don't either. Thanks so much for the help.  :)
Title: Re: Only half a 464 Plus keyboard is working
Post by: Bryce on 11:15, 05 December 19
Ok, then it's most likely just dirt on the membrane as those keys are physically clustered, but don't electrically share a common row or column (unless of course multiple rows/columns have failed).

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 17:40, 10 May 20
Apologies for the late reply. I've finally gotten around to taking a look. I've cleaned the membrane and the connector but the same keys still fail to work. Hmmm. Can't figure it. There's sound, the joystick ports are fine. Everything else appears to work as normal except these keys. Would it need a new membrane? Are they even available?
Title: Re: Only half a 464 Plus keyboard is working
Post by: CrookieMonster on 14:05, 26 May 20
I'm wondering if I'm not cleaning the membrane properly. What should I clean it with?


Quote from: CrookieMonster on 17:40, 10 May 20
Apologies for the late reply. I've finally gotten around to taking a look. I've cleaned the membrane and the connector but the same keys still fail to work. Hmmm. Can't figure it. There's sound, the joystick ports are fine. Everything else appears to work as normal except these keys. Would it need a new membrane? Are they even available?
Title: Re: Only half a 464 Plus keyboard is working
Post by: Bryce on 14:09, 26 May 20
Warm water and soap. It could of course still be a crack in the membrane that's causing the problem.

Bryce.
Title: Re: Only half a 464 Plus keyboard is working
Post by: mark25810 on 22:44, 09 June 20













when I got my 464 plus I noticed some of the F keys were not working, like F1 and another took it apart membrane was ok but was a tad loose at that side so used a bit of electrical tape just to stick it tight like the rest was and it sorted it right away
















Quote from: CrookieMonster on 15:24, 04 December 19
I'm having yet another issue trying to bring my 464 Plus back to life.


I now have a cartridge with BASIC (thanks tjohnson for all of your help) but I'm now finding that a few of the keys on the keyboard are not working (from y to p, Return and some others.


Is there an easy method of working with keyboards to fix this? It's only affecting the right hand side of the keyboard.
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