From the little I can find out the PCS 1000 was actually made by philips

I have no personal experience of it, but it seems it does use a flourescent bulb (which is potentially a good thing as they run cold) and apparently has a shutter of some sort in the enlarger head controlled by the timer. I guess the standby button turns the light on, the "light" button opens the shutter for focussing and the "start" button makes a timed print. If the start button isn't turning the projected light on and off according to the time set on the dial, I guess the shutter isn't working.

This seems to be an unusual enlarger, but potentially could be good - the cold light of the flourescent tube avoids negative pop caused by heat.

Two choices. Either get it working, or junk it and start again with a more traditional unit.

Where abouts in the UK are you BTW?