As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR WOULD NOT RETRACT. WOW MISCOMPARE CAS MESSAGE FOLLOWED SHORTLY AFTER. 2 MINUTES LATER LOUD "THUNK" NOISE FROM BELLY OF ACFT. FOUND NOSE GEAR STRUT PRESSURE LOW WITH 2 O'RINGS ON SCHADER VALVE. REPLACED 1 O-RING AND SERVICED STRUT IAW MM, CH 32-20-00. ALL OPS CKS GOOD.