On the off chance that somebody stumbles on this: I got it to work in the end. After the initial experiments, I noticed the camera refused to charge from a bog-

On the off chance that somebody stumbles on this: I got it to work in the end. After the initial experiments, I noticed the camera refused to charge from a bog-standard USB charger (with any cable). Removing and reinserting the battery restored charging functionality and, as it turns out, the camera also started being visible in PC remote mode. Serves me right for only using the regular on/off switch.