So I did my repair last night. I'd ordered new springs (the gold ones, found via a different headset number) - a set or 4x Sennheiser 036205 HD600 Contact Spring. I'd already gotten in the replacement foam for the headband and ear-pads and inside the cans. Took apart the headphones -...

Ive got your issue too, while replacing the foam I tried to adjust the spring coils and boink, one wire is loose. I think unlike the HD6xxx series which has the wire held in by a PIN which then connects by friction to the spring, in ours, the spring may just directly friction fit to the wire...

Better late than never... my two HD 545's had the foam just finally go totally flat. They just don't make foam that lasts 20 years :) One can order foam replacement ear-pads, inside the cup foam pads (that were also disintegrating) and a new headband over eBay from China. I'm in the process of...

Well, it took some faith, but the dissassembly is simple enough when you know how... as there are no screws involved. So you pull the ear cushions/padding off. Just pull out, the snap out... yes, it takes faith. Behind them is a small foam pad. The headband, where it pivots on the ear...