Can be repaired old quartz or solar watches?

Are old quartz or solar watches worth buying? I saw some aluminum Swatch Ironys at a friend's house, which were from the late 90s or mid-2000s. Looking in the G-Shock database, I found many interesting models, but some were also from the same period (late 90s or mid-2000s) as my friend's Swatches. If these watches break, can they be repaired? Can functional parts be found for such watches, if such parts are possible to replace?

Thank you,

Best regards,

Adrian