Doc uses a magnifying glass to see the time circuit control microchip while Marty looks at the repair instructions.
Doc examines the time circuit control microchip through a magnifying glass.
- "Unbelievable, that this little piece of junk could be such a big problem."
- —Doc Brown
The time circuit control microchip was a device essential to the working order of the DeLorean time machine, and was manufactured in Japan. After the DeLorean was struck by lightning during the Hill Valley Thunderstorm in 1955, sending Emmett Brown back to 1885, it shorted out, burning to a charred color. The lightning also destroyed the flying circuits fitted during the DeLorean's hover conversion in 2015 — meaning the car would never fly again.
Doc's younger self and Marty McFly found the DeLorean buried in the Delgado Mine and recovered the burned-out microchip. New parts available in 1955 were used to replace the microchip allowing the time machine to work again, at least to reach temporal displacement. The resulting assembly of 1955 components — which included vacuum tubes — making up the new time circuit control were attached by straps to the car's hood.