737-300/400 Mcp
Happened to me recently, the MCP "freezes", all numbers displays '8' (except the ALTITUDE window shows 50.000 ft). I could not set the CRS, HDG, SPEED.The A/P disengaged and will not CMD , A/T if engage only in MCP SPEED mode.
Tried to change the source of electrical with the APU GEN, nothing change.
Anybody know the "cure" for this ?