Uploaded February 2021 | Updated September 2026, 2 weeks ago

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I'm trying to find out why my Commodore C64 won't correctly boot a BackBit cartridge.

BackBit Cartridge: backbit.io
Replacement Caps & Fuses (UK): retroleum.co.uk
C64 Service Manual (Page 52 for this C64): zimmers.net/anonftp/pub/cbm/schematics/computers/c64/servicemanuals/C64-C64C_Service_Manual_314001-03_(1992_Mar).pdf
Music is from Turrican C64 version

Timestamps
0:00 The problem
1:20 Address bus
2:12 Bad caps?
4:00 Replacing C58 cap
5:27 Testing
6:20 Results after full recap
7:30 9v line problems
9:30 Testing the 9v line (no SID)
11:00 Testing the 9v line with SID
13:05 Final comments