vaillant 630 r1

[Viper Gas]

hi all, called to a vaillant 630 r1, no display or power but there was 250v at pcb terminals!!!!!
checked pcb and found 5v dc to earth on pcb.
im thinking the display board in knackered?
any other suggestions?
if it is display board why would this have happened?
cheers

DD368

 

[kozak1968]

Lecturer on the vaillant course said unplug the fan and the display will come on indicating a fan fault. I"ve never tried it but worth a go.