B737-300 first officer reported loss of MCP in climb; leading to a decision to return to departure a...

Narrative:

While climbing out at about 29;000 ft MSL we began experiencing multiple instrument errors. The mode control panel completely froze and we were unable to set altitude; airspeed; heading; or course. We also had an MEL of the fuel totalizer on the FMC. Since [our destination] was experiencing strong winds and moderate turbulence; we decided to return to [departure airport]. Enroute back; we encountered thunderstorms and had to receive help from ATC in navigating. We elected to land immediately which required an overweight landing. The captain refused to declare an emergency. I disagreed with this decision.

Original NASA ASRS Text

Title: B737-300 First Officer reported loss of MCP in climb; leading to a decision to return to departure airport; where they made a safe overweight landing.

Narrative: While climbing out at about 29;000 FT MSL we began experiencing multiple instrument errors. The Mode Control Panel completely froze and we were unable to set altitude; airspeed; heading; or course. We also had an MEL of the fuel totalizer on the FMC. Since [our destination] was experiencing strong winds and moderate turbulence; we decided to return to [departure airport]. Enroute back; we encountered thunderstorms and had to receive help from ATC in navigating. We elected to land immediately which required an overweight landing. The Captain refused to declare an emergency. I disagreed with this decision.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1055973
Time
Date	201212
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Component
Aircraft Component	MCP
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 80
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Weather / Turbulence

B737-300 first officer reported loss of MCP in climb; leading to a decision to return to departure airport; where they made a safe overweight landing.