Oric Repair: The Impossible RAM Failure

This episode is sponsored by PCBWay https://www.pcbway.com
What should have been a relatively straightforward repair of an Oric Atmos, turned into a wild chase for the true source of the problem. Tests kept pointing me in one direction, but my gut told me it was something else.

Support Noel's Retro Lab on Patreon: https://www.patreon.com/NoelsRetroLab
You can also support Noel's Retro Lab on YouTube by joining this channel:
https://www.youtube.com/channel/UC2-SP1bYi3ueKlVU7I75wFw/join

Chapters:
00:00 Intro
01:22 Look inside
03:43 Voltages
05:21 Clocks
08:16 RAM
09:17 Diagnostics ROM
12:50 RAM circuit
15:02 ULA
16:08 Power
18:51 Last try
20:38 Testing
21:13 Making sense of things
23:46 Conclusion

Links:
Oric diagnostics ROM https://oric.signal11.org.uk/html/diagrom.htm
Blake's 7 https://www.defence-force.org/index.php?page=games&game=blakes7

Music tracks:
Funky Stars by McKlain https://mcklain.bandcamp.com/track/funky-stars-amstrad-cpc-true-8bit-version
Battro OST by McKlain https://mcklain.bandcamp.com/track/battro-ost
More awesome music by McKlain: https://www.mcklain.com

🛠 Tools I use ➤ https://noelsretrolab.com/tools.html

Connect with Noel's Retro Lab:
Discord ➤ https://discord.gg/ETcCh6J
Facebook ➤ https://www.facebook.com/NoelsRetroLab
Twitter ➤ https://twitter.com/NoelsRetroLab
Instagram ➤ https://www.instagram.com/NoelsRetroLab
Mailing list ➤ https://noelsretrolab.com