As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4425 THE CREW REPORTED THAT DURING THE CLIMB, THE CABIN RATE AND CABIN ALTIMETER REPEATEDLY SHOWED DASHES AND THE CABIN PRESSURIZATION FLUCTUATED EXCESSIVELY. THE CAPTAIN ELECTED TO RETURN TO LGA. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE GROUND CONNECTION SEAL IAW AMM 21-22-04. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.