Noob Questions

[istmedoofer]

Hi,

So been having a read through here today and have some questions about my newly acquired 464....

When booting, I was seeing odd characters appear on the command line, and  then deleted, along with this delete and some of the keys on the bottom row of the keyboard do not respond, I'm getting despondent now that I have a duff AY chip... I'm cleaning the keyboard PCB so maybe that will fix things but if it does not where is the next step, I've got limited equipment to diagnose issues.

When loading from tape, I don't hear any tape sounds, but then a game starts I do hear the music / effects, is something wrong there ?

If I want to test without the keyboard attached, I assume the tape unit needs to be plugged in ?

In desperation is there anyone in East Kent who could do a little work ? 

Doofer.

[istmedoofer]

Hi,

I forgot to mention it's an early z70100 board, May '84

[istmedoofer]

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

[eto]

Any ideas what this could be, any further diagnosis I can do with a multimeter?

which characters appear and which keys do not work?

Generally speaking, it's always good to give all the details you have and/or upload pictures. It's often that small hints/details help a lot to find the actual culprit.

Other than that are there any recommendations as to who could have a proper look & fix this ?

where are you located?

[istmedoofer]

Hi, 

Thanks for the reply!

Yeah my bad sorry, I thought I could attach pics in the forum but looks like I've got to upload them somewhere and then link.

I'll check again once I've put it back together but I think it's was the keys and characters associated with BIT Lane 7.

I'm in the UK, North East Kent..

Regards, 
Martin. 

[istmedoofer]

Hi,

Tried to edit the last post but too late, sorry.

So these keys are dead     z x v , . crtl space del

The characters printed must be some deveration of these there is a . and then special characters I assume from ctrl being pressed.

Just to top it off, it seems to have dies compleatly now, not booting or even the power LED....

[Bryce]

Hi istmedoofer (German in east Kent?),
    a few questions and some info... Do the odd characters appear and get deleted if you boot without the keyboard connected? Yes the tape deck needs to be connected, because the power switch is routed through that connector. Do all keys work otherwise when the CPC has booted to BASIC?
If games load properly and you can hear the sound/music in the game, then all is fine with the analogue side of the AY. The digital part of the AY might still be damaged, but a few tests (including the questions I just asked) will confirm whether the odd characters are due to a bad AY.

Bryce.

[eto]

I've got to upload them somewhere and then link.

It is possible. Just click "preview" if you are in the quick reply editor. This will open the normal editor which allows to attach pictures.

This unfortunately is an annoying "feature" of the forum software which confuses most new people on the forum. 

So these keys are dead    z x v , . crtl space del

They are all connected to bit 7 of the sound-chips I/O port which is a good indication that something is wrong there. I would first check if there is some corrosion or if maybe the connection between keyboard connector and sound IC is working (maybe a crack in the PCB trace). If the connection is present, then the sound IC is probably malfunctioning.

Just to top it off, it seems to have dies compleatly now, not booting or even the power LED....

If the power LED is not working I would check two things first

• does the power supply/monitor still deliver 5V? if yes then
• open the power switch and clean it. After 40 years it's often slightly corroded inside and a good clean will make it work again.

[istmedoofer]

Hi istmedoofer (German in east Kent?),
    a few questions and some info... Do the odd characters appear and get deleted if you boot without the keyboard connected? Yes the tape deck needs to be connected, because the power switch is routed through that connector. Do all keys work otherwise when the CPC has booted to BASIC?
If games load properly and you can hear the sound/music in the game, then all is fine with the analogue side of the AY. The digital part of the AY might still be damaged, but a few tests (including the questions I just asked) will confirm whether the odd characters are due to a bad AY.

Bryce.

Hi,

Haha, no I'm a Brit, bit have been told my username is does mean stupid or something in German ? My wife's family are Hoden ;-)

Thanks for the reply!

Yes the characters appear and get deleted even when the keyboard is disconnected.

All the keys work with the exception of z x v , . crtl space del, I do get a beep when the I use the arrow keys and get to the end of a line....

Regards,

Doofer.

[Rabs]

Hi, 

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

Hi,

I am in Hampshire, so probably an hour or so away (down the bottom of the A3). I have fixed a number of CPCs and unfortunately my dead chip jar contains a few AY-3-8912s. But let's hope it is not the AY as replacements can be expensive or hard to find (although modern emulations are available).

Rabs.

[istmedoofer]

Hi,

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

Hi,

I am in Hampshire, so probably an hour or so away (down the bottom of the A3). I have fixed a number of CPCs and unfortunately my dead chip jar contains a few AY-3-8912s. But let's hope it is not the AY as replacements can be expensive or hard to find (although modern emulations are available).

Rabs.

Hi,

Thanks for the offer Rabs, appreciated, probably a couple of hours in all reality, about an hour to the M25 from here and then whatever happens around the bottom there...

So yeah, been looking at the options and I've found a working Z70100 board that looks really clean for about the same as it would be to potentially replace the AY, so I've rolled the dice and will see how it goes with that I suppose.

If it does work I'll probably offer the old one for spares I'm sure someone would want it for the cost of postage....

Coming early in the week so fingers crossed 🤞

I got the switch working by giving it a good wash through with IPA, didn't even need to take it apart, result, got rid of the static I was hearing as well, happy days.

Looking a modern storage now, M4 or USIfACI like the idea of running CPM....

Servicing the Cheetah 125+ that came with it tomorrow.....

Thanks again.

Doofer.

[Rabs]

Hi,

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

Hi,

I am in Hampshire, so probably an hour or so away (down the bottom of the A3). I have fixed a number of CPCs and unfortunately my dead chip jar contains a few AY-3-8912s. But let's hope it is not the AY as replacements can be expensive or hard to find (although modern emulations are available).

Rabs.

Hi,

Thanks for the offer Rabs, appreciated, probably a couple of hours in all reality, about an hour to the M25 from here and then whatever happens around the bottom there...

So yeah, been looking at the options and I've found a working Z70100 board that looks really clean for about the same as it would be to potentially replace the AY, so I've rolled the dice and will see how it goes with that I suppose.

If it does work I'll probably offer the old one for spares I'm sure someone would want it for the cost of postage....

Coming early in the week so fingers crossed 🤞

I got the switch working by giving it a good wash through with IPA, didn't even need to take it apart, result, got rid of the static I was hearing as well, happy days.

Looking a modern storage now, M4 or USIfACI like the idea of running CPM....

Servicing the Cheetah 125+ that came with it tomorrow.....

Thanks again.

Doofer.

Not problems, yes probably a bit far.  if it does not play out I can sort you out with a 464 "tall key". I have a couple working that are spare.

[istmedoofer]

Hi,

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

Hi,

I am in Hampshire, so probably an hour or so away (down the bottom of the A3). I have fixed a number of CPCs and unfortunately my dead chip jar contains a few AY-3-8912s. But let's hope it is not the AY as replacements can be expensive or hard to find (although modern emulations are available).

Rabs.

Hi,

Thanks for the offer Rabs, appreciated, probably a couple of hours in all reality, about an hour to the M25 from here and then whatever happens around the bottom there...

So yeah, been looking at the options and I've found a working Z70100 board that looks really clean for about the same as it would be to potentially replace the AY, so I've rolled the dice and will see how it goes with that I suppose.

If it does work I'll probably offer the old one for spares I'm sure someone would want it for the cost of postage....

Coming early in the week so fingers crossed 🤞

I got the switch working by giving it a good wash through with IPA, didn't even need to take it apart, result, got rid of the static I was hearing as well, happy days.

Looking a modern storage now, M4 or USIfACI like the idea of running CPM....

Servicing the Cheetah 125+ that came with it tomorrow.....

Thanks again.

Doofer.

Not problems, yes probably a bit far.  if it does not play out I can sort you out with a 464 "tall key". I have a couple working that

Hi,

Hi,

So....

I've done some basic fault finding, the characters appear regardless of whether the keyboard is plugged in, and I've had the keyboard apart and gave it a good clean.

Powering from a new 5V 2A wall wart.

Apart from the edge connectors the main board looks clean, I've gave it a dust off and wipe over with IPA....

Any ideas what this could be, any further diagnosis I can do with a multimeter?

Other than that are there any recommendations as to who could have a proper look & fix this ?

Thanks,

Other than that are there any recomendations as to who could have a proper look & fix this ?

Thanks,

Hi,

I am in Hampshire, so probably an hour or so away (down the bottom of the A3). I have fixed a number of CPCs and unfortunately my dead chip jar contains a few AY-3-8912s. But let's hope it is not the AY as replacements can be expensive or hard to find (although modern emulations are available).

Rabs.

Hi,

Thanks for the offer Rabs, appreciated, probably a couple of hours in all reality, about an hour to the M25 from here and then whatever happens around the bottom there...

So yeah, been looking at the options and I've found a working Z70100 board that looks really clean for about the same as it would be to potentially replace the AY, so I've rolled the dice and will see how it goes with that I suppose.

If it does work I'll probably offer the old one for spares I'm sure someone would want it for the cost of postage....

Coming early in the week so fingers crossed 🤞

I got the switch working by giving it a good wash through with IPA, didn't even need to take it apart, result, got rid of the static I was hearing as well, happy days.

Looking a modern storage now, M4 or USIfACI like the idea of running CPM....

Servicing the Cheetah 125+ that came with it tomorrow.....

Thanks again.

Doofer.

Not problems, yes probably a bit far.  if it does not play out I can sort you out with a 464 "tall key". I have a couple working that are spare.

Hey,

Really appreciate the offer, hopefully this will be the one, but if not, I'll keep you in mind and a trip to the south coast 👍

Frustrating but, that's part of the deal with old kit I suppose. 

Thanks again,
Doofer.