Fixing DVD player

Vicky's DVD player is failed. The symptom is that the player shows "NO DISC" even if actually there's in it. Apparently the pick-up lens needs to be cleaned. So I took it apart and cleaned the lense with isopropanol, and also observed some other weired points: a few condensers had been leaking! ...but still, it came to alive after the cleaning, so now they don't have to use play station 2 for watching DVD now.