What was found
WEIGHT OFF WHEELS, FAN CUT OFF, RECEIVED DISPLAY COOL CAUTION MESSAGE, CONTINUED CLIMB TO 7000 MESSAGE PERSISTED MX ADVISED RETURN TO MKE. A FEW MINUTES LATER F/O'S PFD RECEIVED A DISPLAY TEMP MESSAGE, FOLLOWED BY CAPTAINS PFD DISPLAY TEMP MESSAGE, F/O'S MFD DISPLAY TEMP MESSAGE, AIRCRAFT REMOVED FROM SERVICE. REPLACED RELAYS K7HK AND K11HK ALSO THE AVIONICS COOLING PANEL REF AMM 21-24 AND 24-02 SYS CHECKS GOOD.