GNS530 malfunction

Recently out of the blue we got the following set of malfunctions in our
GNS530

VOR does not receive but a separate DME unit which is coupled on the GNS530
does indicate correct DME. During testing we crosschecked the same VOR with
the NAV2 box and it did function properly.

VLOC mode does not function and continuously generates MSG message "VLOC
needs service"
Both TERRAIN & NAVDATA cards got corrupted.

Up on updating the AIRAC NAVDATA from Garmin the NAVDATA card is now
recognized and NAVADATA is displayed.
The TERRAIN data though is not available (neither the TERRAIN page from NAV
subgroup of pages) and on GPS start up we get the message that "card format
is not recognized".


Before I start investigating the problems with avionics shop and/or Garmin
is there something you can recommend ?
Have you heard anything similar in the past ?


Thanks in advance