C64 Scrambled Video Repair

Troubleshooting and repairing another Commodore 64 board (ASSY 250425) with a weird scrambled characters/flickering lines fault. // Kindly sponsored by PCBWay - Get your first PCBs free! - https://www.pcbway.com/ The IC puller I'm using is a Jonard Tools EX-2, available from various electronics resellers. Here's some handy resources I refer to when troubleshooting and repairing C64s: The Pictorial C64 Fault Guide is here: http://derbian.webs.com/c64diag/ Ray Carlsen's troubleshooting and repair guides are here: http://personalpages.tds.net/~rcarlsen/cbm.html You can get the .bin files for various C64 diagnostics cartridges from World of Jani (in case you want to make your own or try in an emulator): http://blog.worldofjani.com/?p=164 Here's the GitHub with Sven's diagnostics harness: https://github.com/svenpetersen1965/C64-Diagnostic-Rev.-586220-Harness Time stamps: 0:00 Introduction 1:43 Fixing bent Keyboard Connector 2:42 Testing Voltages 5:23 Populating the Board 8:17 Initial C64 Test 9:33 Jupiter Lander Distorted Picture 10:45 Fixing the Cartridge Port 12:31 About the Ultimax Cartridge Mode/More Fixing 18:45 Scrambled Character Issues 21:03 Broken VIC-II? 24:09 Power Issues 28:34 It's not the VIC-II! 34:36 MOS7801 Broken? 35:49 U14 Logic Broken? 38:17 More Testing 39:28 Replacing U14 74LS258 Logic 43:51 More Testing, More Cleaning 44:50 Another Logic Chip? 74LS373 49:32 Thank you and Good Night! ----------------------------------------­------ EQUIPMENT AND TOOLS I USE: https://kit.co/janbeta * TWITTER: https://twitter.com/thejanbeta PATREON: https://patreon.com/janbeta WEBSITE: https://www.janbeta.net TWITCH: https://www.twitch.tv/thejanbeta LBRY: https://open.lbry.com/@janbeta:b YT CHANNEL MEMBERSHIP: https://www.youtube.com/channel/UCftUpOO4h9EgH0eDOZtjzcA/join Thanks for watching! * Stuff marked with "*" contains affiliate links. You don't pay anything extra and I get a little commission from everything you buy through the links (even if you buy something different there). #JanBeta #Commodore #C64 #PCBWay