Print Page - Amstrad CPC 464 (Version B) Repair

Title: Amstrad CPC 464 (Version B) Repair
Post by: NickWilliams94 on 23:43, 21 November 18

First time commenting on a forum, so please be gentle with me.

I've recently embarked on purchasing, servicing & reselling 464's as a hobby whilst being between work at postgraduate studies. Having bought four 464's so far, it is only my fourth purchase on eBay that has thrown up any real issues.

Upon delivery, I connected the 464 to a working monitor, powered it up and discovered that it has an issue with displaying any graphics (I'll add photos to the thread in due course); from what I've researched, it will hopefully be a RAM issue that can be resolved by replacing a chipset, however if this isn't the solution, your advice will be most welcome!

Sent from my iPhone using Tapatalk

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: robcfg on 06:33, 22 November 18

Hi Nick, welcome to the forum!

You are at the right place for helping that CPC.

Good luck!

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: tjohnson on 00:37, 23 November 18

Hi Nick, you'll need to put up a bit more information one thinks.

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: robcfg on 07:35, 23 November 18

Definitely.

Please post some pictures of the corrupted graphics and of your CPC's circuit board.

There are much more board revisions than you can imagine...

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: NickWilliams94 on 22:58, 29 November 18

So having opened up the 464 (it's a MC0044B board) and tested the RAM piggybacking the 4164 chipsets using a good chip, swapping the ULA & CPU for good chips, this didn't solve the issue.

(https://uploads.tapatalk-cdn.com/20181129/0a555b747ca05c737af3a3054e89555e.jpg)
(https://uploads.tapatalk-cdn.com/20181129/097c54c0c78a1bf5e83f753f7c445ad2.jpg)

Can anyone suggest any other ideas?

A CPC464 Hobbyist

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: Bryce on 08:29, 30 November 18

Try running the RAMTest, piggybacking RAM chips will only work for certain RAM failures. A stuck bit or a short inside the RAM will still not boot with piggybacking.

Bryce.

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: NickWilliams94 on 17:28, 30 November 18

Quote from: Bryce on 08:29, 30 November 18
Try running the RAMTest, piggybacking RAM chips will only work for certain RAM failures. A stuck bit or a short inside the RAM will still not boot with piggybacking.

Bryce.

Thanks Bryce, can you point me in the direction of a thread that gives a walkthrough of running the RAM test? This is the first time I've encountered a RAM issue that's required more than piggybacking as a solution!

A CPC464 Hobbyist

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: twox on 17:53, 12 January 19

Hmm, it appears to be the same issue as i have with my Schneider cpc 464. Does your one sizzle when you turn it on? Does it sometimes show anything other than the big rectangle?

Title: Re: Amstrad CPC 464 (Version B) Repair
Post by: NickWilliams94 on 23:06, 10 October 19

No. I've not had any sizzling and I don't get anything else on the screen. :'(

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General Category => Technical support - Hardware related => Topic started by: NickWilliams94 on 23:43, 21 November 18