Author Topic: Why won’t it turn on?  (Read 834 times)

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Offline ukmarkh

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Why won’t it turn on?
« on: 22:37, 23 May 18 »
My Amstrad CPC 6128 will not turn on, any ideas?




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Offline robcfg

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Re: Why won’t it turn on?
« Reply #1 on: 22:54, 23 May 18 »
I'd try to clean the power switch with contact cleaner to begin with, and if that doesn't help, check for broken solder points.

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #2 on: 22:55, 23 May 18 »
I'd try to clean the power switch with contact cleaner to begin with, and if that doesn't help, check for broken solder points.

The power switch does feel a bit stiff as you flick it on and off [emoji848]


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Offline Duke

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Re: Why won’t it turn on?
« Reply #3 on: 23:01, 23 May 18 »
I'd try to clean the power switch with contact cleaner to begin with, and if that doesn't help, check for broken solder points.

Yes.

I just received a "not working" 464 today (cost down, yay).
Two problems. Power socket was slightly loose, re-solder it and then the power switch, although it passed the continuity test (beep!), it must have had too much resistance to power the CPC on. Opening and cleaning the switch and the machine is back to life :)

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #4 on: 23:05, 23 May 18 »
Yes.

I just received a "not working" 464 today (cost down, yay).
Two problems. Power socket was slightly loose, re-solder it and then the power switch, although it passed the continuity test (beep!), it must have had too much resistance to power the CPC on. Opening and cleaning the switch and the machine is back to life :)

What household stuff can I use to clean it?


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Offline Duke

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Re: Why won’t it turn on?
« Reply #5 on: 23:08, 23 May 18 »
IPA if no contact cleaner. In lack of anything chemical, just rub the two contact points clean with some toilet paper, whatever :)

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #6 on: 23:11, 23 May 18 »
Doesn’t look too bad, just wondering how I can strip it with my fat fingers




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Offline Duke

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Re: Why won’t it turn on?
« Reply #7 on: 23:15, 23 May 18 »
Use a screwdriver to bend the metal legs slightly going around the plastic then you can get the cap off.
You could just try to short the two yellow wires, so you know if it's worth opening it or not.

Doesn’t look too bad, just wondering how I can strip it with my fat fingers




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Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #8 on: 23:22, 23 May 18 »
I shorted the two yellow wires and it turned on [emoji1303]


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Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #9 on: 23:28, 23 May 18 »
The culprit, horrible vial red stuff...





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Offline Duke

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Re: Why won’t it turn on?
« Reply #10 on: 23:37, 23 May 18 »
I think that part is supposed to have a bit of grease, what you want to clean is the "platin" knob on the little metal plate and below it in the contact.

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #11 on: 00:03, 24 May 18 »



Now all I’m getting is a blue or black screen [emoji22]




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Offline Duke

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Re: Why won’t it turn on?
« Reply #12 on: 00:07, 24 May 18 »


Now all I’m getting is a blue or black screen

Maybe it's not cleaned good enough and still has too much resistance. Try to short yellow wires again.

Offline ukmarkh

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Why won’t it turn on?
« Reply #13 on: 00:08, 24 May 18 »
Maybe it's not cleaned good enough and still has too much resistance. Try to short yellow wires again.

Only blue screen with shorting [emoji17] But the lights and everything turn on... Maybe Rom chip has gone


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Offline Chinnery

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Re: Why won’t it turn on?
« Reply #14 on: 00:13, 24 May 18 »
(oops, replied to an old post without refresh)

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #15 on: 00:15, 24 May 18 »
First, see if it is the switch.
Unplug it from the board, then VERY CAREFULLY, bob a flat bladed screwdriver between the 2 newly exposed pins. And I do mean very carefully!!!
If it comes on, the switch is dirty/buggered. If not, the issue is elsewhere.

Yeah, I tried that, blue screen...


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Offline Duke

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Re: Why won’t it turn on?
« Reply #16 on: 00:16, 24 May 18 »
Only blue screen with shorting But the lights and everything turn on... Maybe Rom chip has gone

Does pressing DEL make a sound?
It seems to setup the proper colours with the blue screen (rom chip needs to work for that).

Offline ukmarkh

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Why won’t it turn on?
« Reply #17 on: 00:18, 24 May 18 »
Does pressing DEL make a sound?
It seems to setup the proper colours with the blue screen (rom chip needs to work for that).

Held Del key down, no noise. I forget, which is the Rom chip, I’m sure I’ve got spares...

Is it the 40010?




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« Last Edit: 00:21, 24 May 18 by ukmarkh »

Offline Duke

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Re: Why won’t it turn on?
« Reply #18 on: 00:25, 24 May 18 »
Held Del key down, no noise. I forget, which is the Rom chip, I’m sure I’ve got spares...
Ok :/
Check if any of the RAM chips are hot, would be first thing that comes to mind, but tbh. I am not sure if it would get to setup the blue colours without working RAM, iirc. it will crash somewhere in lowerrom before that and leave you with a grey screen/black border.
40025 is the romchip.

No 40010 is the gate array.

Offline Duke

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Re: Why won’t it turn on?
« Reply #19 on: 00:34, 24 May 18 »
If none of the RAM chips are hot (small OKI chips), try to replace the Z80 first as it's in a socket, and they can have faults these days.

Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #20 on: 01:06, 24 May 18 »
If none of the RAM chips are hot (small OKI chips), try to replace the Z80 first as it's in a socket, and they can have faults these days.

Ram chips cool to the touch, changed Z80, no difference, changed 40010, no difference. I’m thinking that bloody ROM chip [emoji22]


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Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #21 on: 01:58, 24 May 18 »
So, after further investigation and sweating buckets, I found out that the ribbon cables from the keyboard are stopping the CPC from starting up!




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Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #22 on: 02:05, 24 May 18 »
Can’t see anything obvious, but will give it a clean and see how we go [emoji848]




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Offline ukmarkh

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Re: Why won’t it turn on?
« Reply #23 on: 02:10, 24 May 18 »

This looks like the problem, it’s rusted at the keyboard base and has destroyed the membrane, I have a spare hopefully




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