Philips PM-5508

I pulled the complete pm5507 manual off the shelf, probably 1966. No exploded views or dismantling details

thanks for trying! I'm going to spray the mechanics from outside and hope it will unlock the presets. I've found on the manual how to align the tuning mechanism after removing one (or both) the RF assemblies, but I'd rather avoid doing that. All the electronics appear mostly OK, probably a lot of the old electrolitics will need to be replaced. Frank

I could unlock all the presets. There's enough room from the top of the mechanism to spray on all the screws and unlock the tuners. A bottom plate can be removed to better access the 4 rightmost tuners. After that, the knobs have to be freed from the shaft as it turns out that they need to slide in and out to allow both tuning and latching of the presets. If they don't slide, it's impossible to latch the preset in the IN position. Now there's one final problem, the knobs look too short! If I install the knobs again, the presets don't latch anymore, the internal shaft has not enough room to extend far enough to allow the mechanism to reach the latching position. This is really puzzling, how can this happen? The knobs are the only platic parts, so I guess they might have shrank just a little. I may have to try working the internal end with a drill bit to make the necessary clearance. This repair is requiring lots of time so far.

Frank

My experience with a colour bar generator was a cheap kit built job - the modulator was very cheap & nasty and fixed frequency.

My solution was to graft in the modulator from a scrap VCR. Most have a preset screw to move the channel - but its not designed for frequent adjustment.