Puma 80e - Cutting Out?

I have just refitted my kitchen and the boiler has started to play up. I first thought it was dust that has been building up but even after a good clean doesn't seem to help.
The following happens:
- There is constant power to the boiler
- The power light suddenly goes off and there is some 'sparking noise' from behind the PCB
- If I then losen the screw and wiggle it a bit, it kicks into life again.

My thoughts are bad soldering on the PCB. Any expert out there who can help?

Thanks.