I am new to electronics, but I started buying kits for practice and learning. One of my kits (Elenco MM8000) isn't working properly and I think I've isolated the problem with the 74HC04 hex inverter.
I looked at the data sheet (https://www.electro-tech-online.com...HC04E-Texas-Instruments-datasheet-8442375.pdf) and noticed that this inverter should always have a high voltage on the output when no voltage is applied to the input and vice versa. However, the chip has been flaky. Sometimes it will have the correct output, but not consistently. Also, once voltage is applied to the input and then is subsequently removed, the output takes a while to restore to its original high voltage setting.
I have purchased other identical chips and found this to be the case even when it has come straight out of the package from the manufacturer. I applied 5 volts to pin 14 and grounded pin 7. Am I missing something? Shouldn't the truth table always be accurate for the corresponding pins listed on the datasheet?
I looked at the data sheet (https://www.electro-tech-online.com...HC04E-Texas-Instruments-datasheet-8442375.pdf) and noticed that this inverter should always have a high voltage on the output when no voltage is applied to the input and vice versa. However, the chip has been flaky. Sometimes it will have the correct output, but not consistently. Also, once voltage is applied to the input and then is subsequently removed, the output takes a while to restore to its original high voltage setting.
I have purchased other identical chips and found this to be the case even when it has come straight out of the package from the manufacturer. I applied 5 volts to pin 14 and grounded pin 7. Am I missing something? Shouldn't the truth table always be accurate for the corresponding pins listed on the datasheet?