With regards to your customer’s concern, it is really a strange coincidence that this fault appeared on two different coil types and really nothing to worry about. I can only apologise for the inconvenience this has caused on this occasion and hope this will not happen again with future purchases.
Depending where a fault is within a coil, the cost for a repair, not in warranty, is likely to be in the region of £310.00 GBP, which is worth spending, given the cost of a new coil.
With regards to the repair under warranty of RMA7640, could you please complete and return the form, which is attached to this email.