Can continuity test cause component damage?

Can continuity test cause component damage?

Generally no. I have used ohmmeters to measure continuity on expensive aerospace electronics and was never concerned. Reliability engineers never warned us about risks.

For your example (LVTTL component), the part will never see a large voltage, the ESD protection circuit will limit the voltage. Connecting an ohmmeter is not the same as connecting a stiff voltage from a power supply. A stiff voltage probably would damage the part.

Some parts without ESD protection could be damaged by an ohmmeter if their absolute maximum input voltage was very low. These types of parts are not common.


Note that your "open circuit" voltage test is probably applying a 10meg load (10M voltmeter) to auto-ranging ohmmeter. Perhaps the ohmmeter had switched into "20 megohm" range mode, which might apply a different voltage than a low-ohms range?

With this Fluke 189 here, with a 10meg voltmeter measuring the output, the 20meg range applies repeating pulses well over 2V, while the low ranges all apply 5.1V continuous.

So, try using the range button to force your meter into various range settings. See which ones give high-ish volts.

ALSO: try measuring a 1meg resistor, 1K, etc., then simultaneously check the voltage being applied. Even if your meter has no 'range' button, perhaps you can force it into a low-voltage ohmmeter mode. Set it to beeper continuity, then jam a 220 ohm resistor across the bananas? (Usually 220 ohms is far too high to trigger the "beep.")

I can't think of any modern circuitry which would suffer damage from an ohmmeter. However, I recall a famous story from WWII, where a new tech was testing some expensive experimental microwave-detector diodes. They all tested bad. In this story, his big black bakelite SIMPSON meter, set to the wrong ohms range, was applying well over 10mA to each one, destroying it.

Then there's the 'Darwin Award' story, where the military tech decided to find out his internal body-resistance by jamming the ohmmeter probes deep into his hands. This supposedly killed him, by triggering heart fibrillation. https://darwinawards.com/darwin/darwin1999-50.html I did something similar with three 9V batteries, salt water, and a soup spoon held in my mouth. No death; not even any pain, however I did see grey "flashes" in my whole visual field when I bumped the connections together. Nikola Tesla would be proud! Or maybe not, since he swore by healthful x-rays aimed at brain, rather than direct electrode connections.

Death's Ray (Mitchell & Webb): https://www.youtube.com/watch?v=8HgejSCHRi8