Garbled Screen! Amstrad CPC 464 Video Failure

I was sure this kind of garbled screen was caused by a faulty CRT controller. It turns out, I was totally wrong! Along the way we take a good look at how video is generated in the Amstrad CPC and what some of the most common RAM failure patterns are.

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Chapters:
00:00 Intro
01:07 First check
01:47 Power issues
04:38 Video generation
07:01 Gate Array
10:47 ROM
12:44 Charred surprise
14:07 Z80
15:12 RAM
18:47 Why?
22:38 Luminance and sync
26:24 Conclusion

Links:
Commented ROM disassembly https://cpctech.cpcwiki.de/docs/os.asm
Amstrad Diagnostics ROM https://github.com/llopis/amstradcpc-...

Music tracks:
Funky Stars by McKlain https://mcklain.bandcamp.com/track/fu...
Battro OST by McKlain https://mcklain.bandcamp.com/track/ba...
More awesome music by McKlain: https://www.mcklain.com

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   / @noelsretrolab  

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#amstrad #retro #repair