One symptom of a bad semiconductor chip is the physical condition of the chip itself. A chip that is charred may have an internal short circuit in it that is causing excessive current and heat in the chip. A chip that is cracked is another symptom of a bad semiconductor chip A cracked chip package (the external casing that holds the actual chip), may indicate that one of the leads inside the package that connects to the chip itself could also be broken or cracked itself.
Bad semiconductor chips will often not work when you apply heat, in the form of heat gun, or cold, in the form of a freeze spray. Chips are rated to work over a given temperature range. For most consumer applications, chip makers will test the chip over a temperature range. The chip maker will often screen parts out that will work over wider temperature ranges for use in space, industrial and medical applications. Semiconductors that are intermittent(sometimes work and sometimes don't) may in fact work if you provide a stable temperature environment.
Failure to meet any one of a chip's DC specifications as specified in the manufacturer data sheet is a symptom of a bad semiconductor chip Direct current (DC) electrical specifications, also know as a chip's DC characteristics are used to measure the static operating performance of a chip. DC specifications include the range of battery voltage a chip will operate over, how much current flows into the power supply lead of the chip and how much current flows into the signal pins of the chip. Other DC specifications include the output high voltage and output low voltage of the chip's output signal leads.
Failure to meet any one of a chip's alternating specifications as specified in the manufacturer data sheet is a symptom of a bad semiconductor chip A chip's alternating current specifications, also known as AC specifications or AC characteristics, are used to measure how fast electrical signals propagate through a chip. If an electrical signal does not propagate through a chip as fast or faster than specified in the AC specifications, it will often not work properly in electronic equipment.