I fixed my DP-558 by using this guide:
http://home.cbkn.dk/DP558/
My PSU was definately broken. I replaced C19, C15, C20 and two smaller ones next to C15 (220 uF 25V and 470 uF 16V). The pieces were somewhat larger than the existing ones, but it wasn't a problem to make them fit. I bought the capacitors at
http://www.elfa.se/no/
It's great to have a working PVR again!