Author Topic: Help to restore a old CPC 6128 (Read 1440 times)

Lulubull · « **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.

Bryce · « **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.

Lulubull · « **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.

Bryce · « **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.

Lulubull · « **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

Bryce · « **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.

Lulubull · « **Reply #6 on:** 10:46, 09 January 20 »

To replace the RAM, where can i buy it ?

Lulubull · « **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 ?

Bryce · « **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.

Lulubull · « **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.

Lulubull · « **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

Bryce · « **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.

Lulubull · « **Reply #12 on:** 11:10, 09 January 20 »

I have see on ebay some RAM extension for 6128. Can work with games ?

Bryce · « **Reply #13 on:** 11:12, 09 January 20 »

No RAM expasion will work after you have removed the PAL chip.

Bryce.

Lulubull · « **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.

TotO · « **Reply #15 on:** 11:25, 09 January 20 »

I have MP you in french to see if I can help.

Bryce · « **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.

TotO · « **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.

Lulubull · « **Reply #18 on:** 11:57, 09 January 20 »

Thanks for your help Bryce i'm going check the idea of TotO.
best regards

Lulubull · « **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.

Bryce · « **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.

Lulubull · « **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

gerald · « **Reply #22 on:** 18:08, 26 January 20 »

Quote from: Bryce 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.

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.

Lulubull · « **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.

Lulubull · « **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.

News:

Author Topic: Help to restore a old CPC 6128 (Read 1440 times)