iz8dwf | Apple IIgs battery leak damage. The not so easy repair @iz8dwf | Uploaded May 2022 | Updated October 2024, 1 hour ago.
Apple IIgs pcb # 8714. Backup battery leakage damaged PCB.
Testing (almost?) all connections around the damaged area, adding parts
and wires to restore full functionality. The clock oscillator drifted out of
frequency enough to bring the NTSC colour carrier out of the detection
range.

Timeline:
00:00 - Welcome
00:19 - Assessing damages
01:20 - Restoring connections
04:20 - Missing video sync
05:51 - ADB port fault
08:05 - Get the colors back
12:54 - Drifted oscillator

Apple IIgs schematics:
applefritter.com/files/2021/03/18/Apple%20IIgs%20schematic.pdf

Music in this video:
Lilac Skies - Corbyn Kites
Accidents Will Happen - Silent Partner