Potterton Lynx

Perplexing problem!
Boiler demand lights up, but fan wont start.
With a gentle tap on the inner casing (front right hand side)fan starts boiler lights.
Fan or Pcb problem? Don\\\'t know.
Repeated by tapping fan - no response.
Repeated by opening Pcb door so vibration would not travel easily to other parts then tapped Pcb and wiring - no response.
Repeated with pcb door open and gently tapped front right hand side of inner casing - ingnites immediatly! Any ideas?

Er, check the connections?

The connections between the boards havefailed, Potterton changed the TELEVISON set up of the boards in the lynx 1 when they lauched the lynx 2 due to this problem (most potterton lads carried rubber bands to stop this whilst they order up the new boards) I strongly advise against you doing this and get yourself sorted with a new mother board, better still get rid of the boiler it must 15 years old by now????

I do have a Lynx2 boiler. Any other suggestions to try? Thanks in advance for any further help ou can supply.