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General Category => Amstrad CPC hardware => Topic started by: 6128user on 17:33, 27 September 10

Title: Problems with CPC 6128
Post by: 6128user on 17:33, 27 September 10
I got this computer but not without problems. Sometimes it's almost impossible to power up... it simply does not. But usually when I can get it to power up, it will sustain the powers and after that I can restart the machines without worries it wouldn't go on anymore. But as soon as I leave it unused about just a few days I have to everytime worry that it wouldn't power up at all.. so what could be wrong with it?


Another problem is that this computer seems to have scandinavian characters already build-in, but how in a heck I can get this important character "|" because without that I can't load anything or change disc drive. Manuals tells me that I should get | letter when pressing Shift and @ but I will get swedish letter Å. Is there any other way to get | letter? I already tried each key with and without shift and no sign of | letter... this drives me mad   >:(
Title: Re: Problems with CPC 6128
Post by: MacDeath on 17:44, 27 September 10
QuoteSometimes it's almost impossible to power up
Monitor or computer ?

the on/Off switcher may be a bit faulty but not totally...
Those are getting old and as the Amstrad has no reset button, the on/Off switch was used a lot when dealing with some bugged stuffs.


Yet another obvious reason may be the power supply plug (the +5V one) who may have a bad contact sometimes...
Check the dust or faulty contacts first.

Perhaps the power on/off should be tested when faulty


Concerning the rest I don't know.
What kind of keyboard do you have ?

On french keyboards, the "|" is replaced by the "ù"...
As in |cpm becomes ùcpm...

But I don't know for other variants...


Also welcome into the "worldwide Amstrad  8 bit computers appreciation society...Elites and world's finest only ..." ;D
Title: Re: Problems with CPC 6128
Post by: TomEtJerry on 18:12, 27 September 10
Hello,

I agree with Macdeath regarding your first problem. The power button has probably dust or rust inside. It is not so hard to clean it, even if I don't think someone has already done a topic talking about this manipulation (that would be useful, as more and more machines have this problem).

For the second problem, that's easy to solve. The character you must type is CHR$(124). If you type under Basic this :

PRINT CHR$(124)

you will see the good character to use to launch Disc commands.

T&J/GPA
Title: Re: Problems with CPC 6128
Post by: Johnny Olsen on 23:47, 27 September 10
I think it's a Danish keyboard you have.
ø = |
Don't use shift but only lowercase  ø   - øcpm or øtape
Title: Re: Problems with CPC 6128
Post by: MacDeath on 00:54, 28 September 10
Danish keyboard ? does it exists ? ???
Title: Re: Problems with CPC 6128
Post by: MiguelSky on 07:51, 28 September 10
Photo, photo !!
Title: Re: Problems with CPC 6128
Post by: orange on 09:19, 28 September 10
I have the same power up problem with the on/off switch. I tried contact spray but it seems to be just a temporary solution, so I just 'wiggle' the switch (with power cord disconnected) before turning on.
I think some contact spray could solve this but iirc its hard to open that switch.
Title: Re: Problems with CPC 6128
Post by: 6128user on 09:52, 28 September 10

photo's won't help because the keys are normal, but the OS chip is not normal and have already scandinavian letters installed. It's not danish but finnish.


Also, I totally forgot one thing: I opened the keyboard and saw a few of these components that one was totally exploded half and others had the top of the part opened up


http://img.alibaba.com/photo/214042625/Integrated_Circuit_IC_Integrated_Circuit_Products_Integrated_Circuit_Parts.jpg (http://img.alibaba.com/photo/214042625/Integrated_Circuit_IC_Integrated_Circuit_Products_Integrated_Circuit_Parts.jpg)


Otherwise I doubt the problem is caused by the power switch... I already checked it that it was working fine and no solderings ripped off.
Title: Re: Problems with CPC 6128
Post by: Bryce on 09:52, 28 September 10
Forget contact spray, they're useless if the switch has years of gunk on the contacts. Open the switch by carefully bending back the metal tabs (making sure you take note of where the spring landed, the one that just shot across the room and under the sofa :D ) and clean the rocker and the contacts properly with alcohol till it shines. Then put it all back together and it should be good for another few years.

Bryce.

Edit: The part in the picture is a ceramic disc 100nf capacitor and will definitely cause the CPC to not start! Replace the broken ones. They're not poled, so you can solder them in either way around. They are there to stabilise the power to each IC.
Title: Re: Problems with CPC 6128
Post by: Grim on 10:02, 28 September 10
Quote from: Bryce on 09:52, 28 September 10
Open the switch by carefully bending back the metal tabs
Illustration below :)
Title: Re: Problems with CPC 6128
Post by: 6128user on 10:03, 28 September 10
Quote from: TomEtJerry on 18:12, 27 September 10
Hello,

I agree with Macdeath regarding your first problem. The power button has probably dust or rust inside. It is not so hard to clean it, even if I don't think someone has already done a topic talking about this manipulation (that would be useful, as more and more machines have this problem).

For the second problem, that's easy to solve. The character you must type is CHR$(124). If you type under Basic this :

PRINT CHR$(124)

you will see the good character to use to launch Disc commands.

T&J/GPA


It will give me character "ö"    :(


oh, wait... it works! XD   ötape  will do to load tapes xD  thanks..


anyway, the current disc drive seems to be failed because it can't read discs at all... I had 3 drives as a backup but both were having broken belt and making obvious noise but this one sounds to work properly, and it does even say if there's no disk in the drive... but no matter what, typing |a or cat or |dir.... it always says "bad command" althought otherwise the drive seems to work.
Title: Re: Problems with CPC 6128
Post by: arnoldemu on 10:09, 28 September 10
Quote from: 6128user on 10:03, 28 September 10

It will give me character "ö"    :(


oh, wait... it works! XD   ötape  will do to load tapes xD  thanks..


anyway, the current disc drive seems to be failed because it can't read discs at all... I had 3 drives as a backup but both were having broken belt and making obvious noise but this one sounds to work properly, and it does even say if there's no disk in the drive... but no matter what, typing |a or cat or |dir.... it always says "bad command" althought otherwise the drive seems to work.
It is possible the drive is not receiving both 5v and 12v.

I assume all the cables are connected?

Do you hear the drive motor going on?

Try: out &fa7e,0 for drive motor off
and out &fa7e,1 for drive motor on

you should be able to hear the drive motor go on/off as you use these.

If you type CAT then the disc motor should go on and you may see the drive led go bright red for a very short time.
Do you see this?

Title: Re: Problems with CPC 6128
Post by: 6128user on 13:24, 28 September 10
Quote from: arnoldemu on 10:09, 28 September 10
It is possible the drive is not receiving both 5v and 12v.

I assume all the cables are connected?

Do you hear the drive motor going on?

Try: out &fa7e,0 for drive motor off
and out &fa7e,1 for drive motor on

you should be able to hear the drive motor go on/off as you use these.

If you type CAT then the disc motor should go on and you may see the drive led go bright red for a very short time.
Do you see this?


Yes the with those commands I can hear motor going on and off.

But the led is on all the time as soon as I power up the amstrad itself and when typing cat command, it's just blinking a bit.
Title: Re: Problems with CPC 6128
Post by: Xyphoe on 13:32, 28 September 10
Quote from: 6128user on 13:24, 28 September 10
But the led is on all the time as soon as I power up the amstrad itself and when typing cat command, it's just blinking a bit.

Oooh now that rings a bell ... I think *ages* ago I had the same thing on a 6128, the light stayed 'constantly' on ... but this was a long time ago and my memory is very fuzzy on this. I know it was around the time I took the drive out, took it to pieces and gave it a good clean, along with everything else within the membrane - then it behaved. I think. Did I do anything special? I'll rack my brains and have a think.
Title: Re: Problems with CPC 6128
Post by: arnoldemu on 13:37, 28 September 10
Quote from: 6128user on 13:24, 28 September 10

Yes the with those commands I can hear motor going on and off.

But the led is on all the time as soon as I power up the amstrad itself and when typing cat command, it's just blinking a bit.
BTW, I am thinking of writing a test program that can be used to verify parts of the operation of drives to help future problems.
Title: Re: Problems with CPC 6128
Post by: Bryce on 13:44, 28 September 10
The drive LED is always slightly ON and blinks brighter when the disc is being accessed. However, the broken 100nf capacitors you mentioned earlier could cause several functional failures including disc access, so before you have replaced these, I wouldn't spend much time analysing other issues as it's just a waste of your time and the drive might work perfectly normal after the caps have been replaced.

Is the CPC physically damaged, or did you get the mainboard without the case? The reason I ask is that these caps can't explode or break by themselves, it must have been physically mis-treated at some time.

Bryce.
Title: Re: Problems with CPC 6128
Post by: 6128user on 14:28, 28 September 10
I have no idea... I got it second hand and this computer is originally removed from school so I presume it is possible that the kids were not treating the "good old school" amstrad properly. I also saw some weird stain like something would have leaked at the mainboard and I think it's not something that was spilled over the keyboard because the keyboard itself is working fine and no sticky keys at all.
Title: Re: Problems with CPC 6128
Post by: arnoldemu on 14:33, 28 September 10
Quote from: 6128user on 14:28, 28 September 10
I have no idea... I got it second hand and this computer is originally removed from school so I presume it is possible that the kids were not treating the "good old school" amstrad properly. I also saw some weird stain like something would have leaked at the mainboard and I think it's not something that was spilled over the keyboard because the keyboard itself is working fine and no sticky keys at all.
we had cpc's at our school. normally the keys were covered in mud or similar, because we would do computing after p.e.

Is this school in the county of Gloucestershire?
Title: Re: Problems with CPC 6128
Post by: 6128user on 16:55, 28 September 10
Quote from: arnoldemu on 14:33, 28 September 10
we had cpc's at our school. normally the keys were covered in mud or similar, because we would do computing after p.e.

Is this school in the county of Gloucestershire?


LOL. I am living in Finland and the computer was from Finland as well with scandinavian (finnish) letters.
Title: Re: Problems with CPC 6128
Post by: Cholo on 19:13, 28 September 10
Quote from: MacDeath on 00:54, 28 September 10
Danish keyboard ? does it exists ? ???
Indeed, my first 464 had genuine "æøå" chars on the keyboard and "inside" as well. I recall it took me a good while to figure that the odd "|" char in all the english mags was actually "ø". If i understand right then "ø" is pronounched the same way as the swedish, norwegian and finnish "ö". The danish basic rom has also been uploaded before (if i remember right). Cant recall seening a finnish rom tho, so that may be quite rare amstrad you got there. Aint got a danish keyboard now, but if you look in the danish amstrad magazine "Amstrad Bladet" (i think we got em on the wiki) then there are som adds that shows the "danish keyboard" layout (and youll notice the "øTape" like commands in the typein section).
Title: Re: Problems with CPC 6128
Post by: Gryzor on 08:01, 29 September 10
Quote from: arnoldemu on 13:37, 28 September 10
BTW, I am thinking of writing a test program that can be used to verify parts of the operation of drives to help future problems.


Please do, please do!
Title: Re: Problems with CPC 6128
Post by: 6128user on 09:08, 29 September 10
Nice! It worked! I just opened the power switch and rubbed the contacts with contact spray moistured cloth and now it works like a dream. Yeah, I really noticed the power switch was oxidized because just touching the switch when on, caused it to make noise and "pixelations"...


thanks guys.


Oh btw, the keyboard layout is completely normal (UK standard?) but the ROM circuit itself is loaded with the scandinavian letters overriding the normals.

And the floppy drive issue does not bother me because I am already using the trick of adding 3.5" floppy drive as primary drive to amstrad. But what a heck? I am now missing the lovely nostalgic "charisma" of using tapes... well, it's at least easier with the tape connections because now I do not need to record data into real cassette as with my first CPC464.
Title: Re: Problems with CPC 6128
Post by: Bryce on 09:38, 29 September 10
Even if all seems to be working properly, I'd still advise you to replace the broken capacitors. The CPC may seem to work properly most of the time, but it will have hidden random bugs that could ruin the experience. Depending which ones are broken, this could cause random memory corruption, I/O function, sound and graphics anomolies. So it's worth the 30mins and 1 or 2€ it'll cost.

Bryce.
Title: Re: Problems with CPC 6128
Post by: redbox on 13:47, 29 September 10
Quote from: 6128user on 09:08, 29 September 10
caused it to make noise and "pixelations"...

That's interesting, as this is what happens to mine sometimes.  Will have to take a closer look...
Title: Re: Problems with CPC 6128
Post by: arnoldemu on 14:05, 29 September 10
Quote from: 6128user on 09:08, 29 September 10
Nice! It worked! I just opened the power switch and rubbed the contacts with contact spray moistured cloth and now it works like a dream. Yeah, I really noticed the power switch was oxidized because just touching the switch when on, caused it to make noise and "pixelations"...


thanks guys.


Oh btw, the keyboard layout is completely normal (UK standard?) but the ROM circuit itself is loaded with the scandinavian letters overriding the normals.

And the floppy drive issue does not bother me because I am already using the trick of adding 3.5" floppy drive as primary drive to amstrad. But what a heck? I am now missing the lovely nostalgic "charisma" of using tapes... well, it's at least easier with the tape connections because now I do not need to record data into real cassette as with my first CPC464.
excellent. I hope I can fix my 664 the same way.
Title: Re: Problems with CPC 6128
Post by: MacDeath on 15:13, 29 September 10
 
QuoteI also saw some weird stain like something would have leaked at the   mainboard and I think it's not something that was spilled over the   keyboard because the keyboard itself is working fine and no sticky keys   at all.
Were they looking porn on this CPC ? ???
Quote
the keyboard layout is completely normal (UK standard?)
Easy : QWERTY or AZERTY ?

Does it features a Ñ key ?


Concerning the disc drive, perhaps your disks are dead...



I wish we had Amstrad at school instead or Thomsons MO5 and TO7... even MO6 and TO8 would have been better...
Title: Re: Problems with CPC 6128
Post by: 6128user on 13:03, 30 September 10
It's qwerty, of course. And no, can't find that special key.


And I checked that disk are no dead because I tried NEW disk and still the amstrad says bad command.


I have two packets of Maxell CF2 10 unopened 3" disks... now totally 19 unopened disks left  ;)
Title: Re: Problems with CPC 6128
Post by: Aapo on 07:11, 16 August 12
Quote from: 6128user on 10:03, 28 September 10
anyway, the current disc drive seems to be failed because it can't read discs at all... I had 3 drives as a backup but both were having broken belt and making obvious noise but this one sounds to work properly, and it does even say if there's no disk in the drive... but no matter what, typing |a or cat or |dir.... it always says "bad command" althought otherwise the drive seems to work.

I know this is old topic but I just fixed my own CPC6128 by replacing old disc belt. After the replacement the drives sounds to work properly but I had the same problem: it always says "bad command" (unless trying to drive it empty, the it says no disc).

After few hour thinking I noticed that guider between read/write head and stepper motor drive worm was little misplaced. I slightly moved it (be careful!) and after that the driver worked correctly (it could have been also that the drive worm had just got stuck after all these year in closet).

I hope this tip helps someone.
Title: Re: Problems with CPC 6128
Post by: endangermice on 18:10, 18 August 12
One of the first things I usually do to eliminate or confirm its a power switch problem is to disconnect the original switch and place a jumper over the pins. If the cpc powers up normally each time the jumper is attached then the switch is as fault. If not there's something else wrong.


One of my spare 6128s is currently only powering up randomly. On the times it doesn't power up properly I get a white screen. I suspect the caps need replacing and that the fault lies in the reset circuit. Once the machine is one it behaves perfectly and will soft reset all day long, it's the hard resets that kill it!


Sounds likes you're well on the way to getting it fixed - definitely replace the caps as Bryce says if they're faulty they can cause a whole host of random issues!


Arnoldemu - do you live in Gloucestershire still? I'm Cheltenham based - so you might be just up the road from me!
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