Author Topic: Help to restore a old CPC 6128  (Read 2300 times)

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Offline Lulubull

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Help to restore a old CPC 6128
« on: 22:29, 08 January 20 »
Hello,
I am new on the forum and i would like to "restore" my CPC 6128. I have already saw some topics with the problem i have and i have saw, this problem is the RAM. I need your help because i don't understand the history with the PIN. The CPC  Thanks in advance.
Best Regards.
P.S : Sorry for my bad english. I am an French student.

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #1 on: 09:36, 09 January 20 »
Hi Lulubull,
      yes, that looks like a RAM issue. Do you have the equipment/skills to replace the RAM? Or are you looking for someone to do the repair? If you want someone to swap the RAM you can send it to me.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #2 on: 09:51, 09 January 20 »
Hi Bryce,
Thanks to reply me. In fact, i have the equipment to do that. I understand easily with pictures so i can do that. I have a soldering iron to replace the RAM. If i need other things to replace the RAM, tell me. I can buy stuff for that.
Best regards.

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #3 on: 10:13, 09 January 20 »
Well you need to firstly find out which RAM chip is causing the problem. Then all you need is a new RAM chip and IC socket.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #4 on: 10:19, 09 January 20 »
Ok, how i check a RAM chip ?
And i supposed the first RAM ship is the IC119 to IC126.
BR

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #5 on: 10:25, 09 January 20 »
Actually no, the lower 64K is on the right, IC127 - IC134. Unless one or more RAMs are getting very hot, you will need some way of replacing the firmware ROM with an EPROM containing Geralds RAM Test to know exactly which chip has failed.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #6 on: 10:46, 09 January 20 »
To replace the RAM, where can i buy it ?

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #7 on: 10:48, 09 January 20 »
And i have reed on another post, you said we can switch the lower and the upper because one of them is not necessary to boot the CPC. I'm wrong ?

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #8 on: 10:50, 09 January 20 »
They're not made any more, so ebay is the only place to get them.
It doesn't sound as if you have much electronics experience. Are you confident that you can swap out RAMs without damaging the computer further?

Yes, you can replace the PAL chip with some wire bridges and that will cause the CPC to use the upper 64K instead.


Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #9 on: 10:57, 09 January 20 »
My father have much more skill in electronics. So when i understand the different step, he replace the RAM for me.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #10 on: 11:03, 09 January 20 »
I check out for ebay and i see that's difficult to find the RAM. If we switch the upper and the lower, they have any dangers or issues if you launch games or other programms ?
If not, i think i do this think if it's possible of course.
BR

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #11 on: 11:07, 09 January 20 »
Swapping is normally only done for test purposes, but you could do it permanently. However, you then only have a 64K computer, so any games needing more RAM will not work.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #12 on: 11:10, 09 January 20 »
I have see on ebay some RAM extension for 6128. Can work with games ?


Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #13 on: 11:12, 09 January 20 »
No RAM expasion will work after you have removed the PAL chip.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #14 on: 11:18, 09 January 20 »
So the only way is to replace the PAL chip. The hardest part is to find a working PAL ship on ebay.

Offline TotO

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Re: Help to restore a old CPC 6128
« Reply #15 on: 11:25, 09 January 20 »
I have MP you in french to see if I can help.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #16 on: 11:26, 09 January 20 »
You don't need to replace the PAL. It most likely works fine. You only replace the PAL with wire links to swap the upper/lower memory banks for test purposes. While the links are in place, the machine will only be 64K and RAM expansions will not work.

All you need to do is establish which RAM chip is bad and replace that.


Bryce.

Offline TotO

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Re: Help to restore a old CPC 6128
« Reply #17 on: 11:32, 09 January 20 »
My idea is to send him a diagnostic board to display the faulty RAM without alterate anything on the CPC.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #18 on: 11:57, 09 January 20 »
Thanks for your help Bryce i'm going check the idea of TotO.
best regards

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #19 on: 17:40, 26 January 20 »

Hello everyone,
Sorry for the late but with TotO, we found the problem. In fact, the problem is due to a RAM Ship. But we haven't found the exact RAM Ship that isn't working. I upload 2 photos. I can't find the RAM Ship. If anyone could help me, I really thank him. Thank you in advance.
Best regards.

Offline Bryce

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Re: Help to restore a old CPC 6128
« Reply #20 on: 17:44, 26 January 20 »
Maybe @gerald can confirm this, but as far as I know, that means IC127 (Top right chip) is bad.

Bryce.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #21 on: 18:05, 26 January 20 »
Thanks for your help Bryce. If you need more pictures or others about the cpc, tell me.
Br

Offline gerald

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Re: Help to restore a old CPC 6128
« Reply #22 on: 18:08, 26 January 20 »
Maybe @gerald can confirm this, but as far as I know, that means IC127 (Top right chip) is bad.

Bryce.
I confirm.Bits are displayed from top in order bit 7 to bit 0.Here bit 0 is failing, which on bank 0 is IC127.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #23 on: 18:19, 26 January 20 »
Thanks you Gerald for your help. I see with TotO for replace the RAM Ship IC127. If the Amstrad work, i tell you.
Best Regards.

Offline Lulubull

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Re: Help to restore a old CPC 6128
« Reply #24 on: 16:33, 09 February 20 »
Hello everyone,
I come with good news. My CPC 6128 work again ! Finally, i change the IC127 and replace by a new one. The game work with no problems. I post 2 pictures below this post. TotO help me a lot with this problem. Thanks to everybody for the help !
Best Regards.