Hi Henrik,

The issue with the hardware PWM was that it doesn't produce a nice square wave, and even at 100% (255) duty is still sending a signal rather than full line level. The net result was that the LED drivers were running around 60% when the PIC was outputting full duty cycle. Using Darrels software PWM I get a nice square wave, which at 0 duty cycle I get 0 volts, at 255 duty I get 5v and full Mark to Space ratio. (ie a solid line with no pulses), which is what you would expect.

I don't think it's a timing issue as I've knocked up a version where the RTC works, and port C1 and C2 drive the LEDs, just when I copy that code to my main program, comment out the reference to CCP registers the resulting HEX causes the clock to function as described.

My only option is to manually modify the PCB to use port E1 and E2....