B737-300
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 109; Flight Crew Type 109
Confusion; Human-Machine Interface
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
We were starting a descent from FL250 to FL240 when we saw a flash of light and we experienced a total MCP and autopilot failure. We notified ATC and reported the equipment and autopilot failure along with a possible static discharge; but quickly decided the flash of light we saw was the MCP going to bright before it failed. ATC asked if we had a lightning strike and we told them we had not. After landing and contacting Dispatch and Maintenance we powered down the aircraft and all systems returned to normal after powering back up. Maintenance Control said our aircraft had a history of MCP failures; so it was replaced at our next destination.After thinking about the event and even though I don't believe we encountered a lightning strike; we probably should have had Maintenance perform a lightning strike inspection as well.
After suffering the loss of the MCP and autopilot in a 'flash of light' event the flight crew of a B737-300 later considered they might better have had Maintenance do a lightning strike inspection as well.  They had initially believed the flash was the result of MCP lighting going to full bright before extinguishing completely.