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Amstrad Support-Repair

Started by retrorepair, 03:53, 29 November 10

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redbox

Quote from: arnoldemu on 16:59, 13 January 11
Cleaning the power switch fixed 2 of my cpcs.

Please can you tell me how you did this?

Had a search and couldn't find anything.

arnoldemu

Quote from: redbox on 17:40, 13 January 11
Please can you tell me how you did this?

Had a search and couldn't find anything.
This is for a CPC (6128 in my case):

1. I turned over computer and removed all screws

2. turned it back over, lifted the case carefully and carefully  removed the keyboard connector (cpcs).
3. then locate the power switch. On cpc464 it is screwed in. On 6128 it is just held in place by tabs in the plastic case.

In both cases there are 2 wires and a connector to the main board. Once removed the mainboard has a connector with 2 pins on it. Clean this gently with sandpaper, you could also check it is held in the pcb by wiggling it a bit, and if it's not, turn the board over and re-solder it's connections.

You could also try resoldering the wires onto the back of the switch.

3. Remove connector from main board (unscrew switch on cpc464) and lift the switch out.

4. looking at the switch you will see it has a black metal bracket which goes around the sliding part, and over the back. it has 2 clips on each side that bend over and grip onto the body of the switch.

using a flat head screw driver (thin head), gently insert and twist between the tab and the body of the switch so that the tabs bend outwards enough to not hold onto the switch.

5. you should then be able to use the screw driver to prise it away from the front of the switch. by putting the screwdriver between the front flat piece (where the slider is) and the body of the switch.
Watch out because some bits will fall out ;)

6. when you remove this part you will now have:

a. the metal bracket thing you just removed.
b. the slider (has a plastic peg on one end, some grease and a small spring).
c. the body of the switch (has the wires comming from it)

there is a  thin metal piece inside the switch, it has two "notches" near the middle on both sides of it. This positions it within one of the contacts.

after removal there will be 2 contacts inside the switch itself. one is circular, the other stands up. the metal piece you removed just sits on these and the plastic peg on the sliding part moves over it to make and break the connection.

7. using some sandpaper clean both connectors inside the switch (folding the sandpaper to make two rough sides worked well). gently clean the connectors by rubbing them with sandpaper. it is important to make these shiny and clean. you may need to use wd40 to clean them up. (or other thin spray based penetrating oil).

8. then clean the underside of the metal piece (with the notches), you may see where it actually makes contact with the parts inside the switch, so clean these bits.

9. once done carefully drop this back into the switch body, making sure it sits correctly on the contacts.

10. Now put the sliding part back in and hold it gently against the metal part and put the bracket over the top.

11. the tabs can be squeezed back to make them hold again, using some pliers or similar.

12. once done connect it back up to the pcb and test it.

It is possible cleaning it will not make a difference; I found this with one switch and after replacing it (with a spare I had), it then worked great.

generally the switch needs cleaning if the cpc just doesn't switch on (led is off), or it doesn't always switch on when you try it, or perhaps touching or knocking the switch while it is on will cause it to turn off or crash.

The other things to check are the power connectors, here it's not so easy to clean.
you could try some sandpaper in the case where the connector has a pin in the centre, or perhaps use some wd40 and some cotton buds, but getting into it is not easy.
you could also resolder it's connections.
If you find the power cable is loose and the computer will turn on/off or crash if you wiggle it, then look at this.


One thing I did find is that the expansion and disc drive connectors get dirty and any plugged in expansions will be unreliable (crashing when connected, roms startup message not appearing)
cleaning the connection with an eraser or similar worked ok if the connector was a little dirty, but using cotton wool buds and some baby wipes, then drying it and using an eraser worked a lot if the connections were really dirty/dusty. (e.g. from storing the computer in an attic room ;) ).

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redbox

Thank you for such a comprehensive explanation.

Can't wait to get inside and clean mine up!

arnoldemu

Quote from: redbox on 18:48, 13 January 11
Thank you for such a comprehensive explanation.

Can't wait to get inside and clean mine up!
np. I did make some photos, but they just ended up being far too blurry to be useful.


My games. My Games
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Bryce

When you're taking pictures of PCBs and bits of computers you should:

1) Always use a tripod - Avoids blurred pictures.
2) Turn off the flash and use very bright room lights - Avoids over exposure and nasty reflections.
3) Don't take the picture up close, place the camera further away and zoom in on the object - Avoids shadows.
4) Always take the pictures at a slight angle - Also reduces reflections.

If you are taking a picture of a CRT, spray it with hairspray first to avoid reflections, but don't do this on an LCD / TFT because you'll never get it off again. Only glass screens should be coated like this.

I usually take 2 or 3 pictures of ever bit, because you'll always get bad pictures in between.

Bryce.

Gryzor

1. Not everyone has one :) Plus, we usually shoot hardware from above, with the subject lying on the floor/bed/desk/toilet seat/whatever. So it's not always possible to use it even if you have it!
2. If you go for ambient light then you should check your colour temperatures. But yes, flash looks awful on everything, unless you use a diffuser (easy to make by yourself with some rice paper maybe)
3. You're right about the shadows, but there's another problem with close shots - and far shots with zoom, as well: distortion of geometry. The best thing is to use a high-megapixel camera from a certain distance and then crop it. This minimizes both shadows and geometry problems.
4.Right on!

I used to take photos on sunny afternoons, placing the piece of hardware right next to my balcony door, then shooting from above. No shadows, plenty of natural, smooth light, neutral temperature, good geometry.

arnoldemu

Quote from: Bryce on 11:10, 14 January 11
When you're taking pictures of PCBs and bits of computers you should:

1) Always use a tripod - Avoids blurred pictures.
2) Turn off the flash and use very bright room lights - Avoids over exposure and nasty reflections.
3) Don't take the picture up close, place the camera further away and zoom in on the object - Avoids shadows.
4) Always take the pictures at a slight angle - Also reduces reflections.

If you are taking a picture of a CRT, spray it with hairspray first to avoid reflections, but don't do this on an LCD / TFT because you'll never get it off again. Only glass screens should be coated like this.

I usually take 2 or 3 pictures of ever bit, because you'll always get bad pictures in between.

Bryce.
thanks. I did everything wrong! that explains it. I hold it and take loads of pictures and pick the best. So I am lucky I get some results.
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redbox

Quote from: Gryzor on 12:03, 14 January 11
I used to take photos on sunny afternoons, placing the piece of hardware right next to my balcony door, then shooting from above. No shadows, plenty of natural, smooth light, neutral temperature, good geometry.


Works well in Greece.  Not so well in Northern Europe...  ;)

Gryzor

Hahaha :D You got a point there!

steve

@retrorepair, while I would be reluctant to send my computer abroad for repair (if it was broken), I might be tempted if you could upgrade a 464plus to a 6128plus by adding 64k ram and floppy disk controller components, even better would be if you offered a kit of parts so I could do it myself.

Thanks.

steve

I have a CPC 464 with a broken 1 key, so I am thinking of stripping it down and selling it as spare parts, so if you need any part send me a PM and I will see if I can help.

I do not intend to remove any chips except the rom (maybe), so the circuit board will be sold as a complete and working board.
Either I sell the keyboard whole with one broken key or I sell the keyswitches, tops and membrane separately.
The cassette mechanism and its circuit board may be sold as a complete unit, or I may sell the operating buttons separately.
The upper and lower sections of the case will be available separately, with or without cassette lid is undecided.

I won't know about prices until I know what people want from it.

So if you need any bits for your CPC 464 let me know please, and we can discuss it.

Bryce

Why would you bother removing the ROM? It probably won't survive the "operation" and the image is available online, so you can burn it to a new EPROM anytime you like.

Bryce.

steve

The rom is in a socket and someone might want it.

Also, I might need the rom to put in my Nascom when I get it working again, to make it CPC compatible.

Bryce

Oh, ok, the ROMs in mine are all soldered in except in one, where I replaced it with a socket myself.

Bryce.

Sara

Hey people,
I have found my old amstrad cpc464 and wanted to check if it is working properly and also have a bit of the rivival with the Barbarian game that I found (I haven't played it since I was about 6  - I'm 25 now! lol). Everything was fine until I found that the play button no longer works. The rewind and forward buttons work fine as does the eject/stop button but nothing happens when I press play. Has anyone got any ideas on how this can be fixed? Does anyone know a DIY way at all?

Cheers

Skunkfish

Hi Sara,

If I remember correctly the tape motor won't start until you type RUN" and then press a key (I think, it's been a few years).

Have a look at the guide below to see if it helps:

http://www.cpcwiki.eu/index.php/A_guide_to_running_software_on_a_real_Amstrad_CPC/CPC%2B_computer
An expanding array of hardware available at www.cpcstore.co.uk (and issue 4 of CPC Fanzine!)

arnoldemu

welcome Sara!

Please follow the instructions for loading from the link.

What you should see:

RUN"
Press PLAY then any key

After pressing a key you will hear a click which is the tape motor switching on. The tape should turn.
If you turn the volume to maximum (on the cpc464) you then should be able to hear the loading sound.
It should give a response like "Loading xxxx block 1".

If there is a problem, it may give "Read error a" or "Read error b" or show nothing.

Please update us with your progress and then we can help you more if there are problems.


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AMSDOS

Hi Sara and Welcome.

The others have it pretty much covered and hopefully that's all it is, sadly if your doing that and the thing still isn't working finding a replacement part maybe tricky. Back in it's day we had to get one of the main components replaced cause the tape wasn't winding through properly and back then it was a costly exercise!  :(  (We could tell it wasn't working like it should cause the tape was speeding up and slowing down). Fortunately though Tape Decks are funny things and read errors can mean any number of things.
* Using the old Amstrad Languages :D   * with the Firmware :P
* I also like to problem solve code in BASIC :)   * And type-in Type-Ins! :D

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arnoldemu

Other options available are:
1. buying and fitting a replacement tape belt (available on ebay uk)
2. cleaning the heads and adjusting the azimuth screw (simple job)
3. giving up on the tape, and soldering your own connector on, and somehow getting the sound into it (either via a pc's sound card or another way).
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Trotzdem

The disc - drive from my CPC 6128 doesn't work anymore. I changed the drive belt and after a few hours it simply stopped reading discs, right in the middle of loading "Hanse" (original disc).

I guess that could be a calibration error or something with the read/write head, so without the right equippment one won't be able to fix it (got the repair manual, and I don't even know some of the devices required).

On the other hand: instead of sending the drive around the world I can also buy a few 664s or 6128s and hope there are working drives in them. But in the long shot (ok, it is quite long already considering the release date of the 6128, but I guess it will get even longer :D) there will be people needed who can make failing parts work again, in order to keep the machines alive.

Bryce

Have you inspected the drive-belt since it failed? Sometimes they fall off after a while if they are slightly off line, or if the wheels weren't cleaned completely.

Bryce.

Trotzdem

I guess I'll look into that. Probably should have gotten to this idea myself, thank you :)

lynwen

Quote from: arnoldemu on 11:43, 19 May 11
Other options available are:
1. buying and fitting a replacement tape belt (available on ebay uk)
2. cleaning the heads and adjusting the azimuth screw (simple job)
3. giving up on the tape, and soldering your own connector on, and somehow getting the sound into it (either via a pc's sound card or another way).
Please can you tell me what is the azimuth screw and where are the heads?? I'm a novice

Thanks  :)

Bryce

If you press play on the tape deck with the lid open, you'll see the tape head move forward. Left and right of the head are two small screws. The left one is the Azimuth screw. Turning this adjusts the height of the head. Don't touch it if your deck is loading tapes ok.

Bryce.

steve

@Lynwen, the trade-in post, if they are still trading, also list 464 head alignment kits.

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