Heating timer controls not working.

Hi, could someone please help me with my problem. My boilermate 2000 timer has suddenly stopped working, it's the mechanical type.
Central heating is only controlled via thermostat now, even with timer switch set to off it still works through the thermostat. I've replaced the clock but to no avail.The clock still has power,ie it's still turning it's just that it no longer controls the bm2000.
I had acb replaced by BG around a year ago and noticed at the time he had only j4 connected but it was working fine so thought it must be the new board. Looking on here I realise that's not right and probably why my heating bills have increased.
Thanks in advance.
Lee

Bm 2000.
Sounds like it is the ACB
But
The jumpers should be on 1,3 & 4.
Number 5 is used when fitting the ACB
Then removed.
I have come across this before last time was BG.
Paper work comes with the ACB if genuine so should be idiot proof.
Mike