At last we have discovered the secret behind all of our chip failures. We didn't realize it, but some chips apparently have a built-in fuse like the one illustrated above, which was discovered on a Dallas Semiconductor DS2151Q single-chip T1 transceiver. Apparently, this die fuse is still working although now the chip is not. We wonder if the sign changes to "Bad Die Fuse" or "Replace Die Fuse" when the fuse blows. This chip is the same integrated circuit that contains the Mister T and Made in Texas silicon doodles.

The chip containing this artwork was loaned to us by Chipworks, a company that is an international provider of reverse engineering services, analyzing the circuitry and physical composition of semiconductor chips and electronics systems for competitive study, intellectual property support, and reliability assurance.