New Panasonic Multi split AC issues

[ISR]

We installed our first tri-zone minisplit system 10 days ago. Panasonic CU-3KS19NUB with 3 indoor units CS-MKS7NKU. I have many questions since this is the first multisplit system we have installed but we were called back yesterday with the report that one zone didn't seem to be cooling. One zone seems to be working off and on. I am getting a E12 diag code (mis wiring,blown fuse,Power relay failure, outdoor PCB failure, compressor failure.) I did not have any diag. lights on in the outdoor unit. I called tech support yesterday and they told me to take DC volt reading on ternimals 2 and 3 (14.7) then had me remove the two line wires from terminals 2 and 3 test again (1 v) He said indoor board was bad. I tested the other two zones that were working fine and the tested the same. When I called back he said my meter is bad. I don't think so bro!
With very little knowledge on these systems and no info I feel like my hands are tied. Looking for any education on these systems and suggestions to try.
The other problem is, when I arrived, all remotes were set for 70 the entire floor was at 64 deg and all units were still cooling with the exception of the one problem zone.
Is there any site I could find more info for troubleshooting

[martinw58]

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