Grundig Cd 301 ((link)) -

First-generation Philips-based circuit boards used double-sided PCBs connected by small copper rivets called "griplets." Over time, thermal expansion can cause these solder joints to crack, leading to intermittent tracking issues or channel dropouts. Reflowing these joints is a standard DIY fix.

This is a goldmine. The CDM-1 transport is well-documented. The schematics are available for free online (HiFiEngine). It is a relatively easy unit to recap and modify. grundig cd 301