Jan,
I know all about those very tiny lost tracks fiddling with T1. Glad you were able to repair!
Your earphone jack may be shorting to ground (Know issues). Try removing the electrolytic just before the socket and putting in circuit with an external socket. That should prove the fault. I also suspected IC10 but it was much simpler than that :)
73 de Eddie ZS6BNE
Eddie Leighton