Latch-Up?

[Jester]

Simple little 555 circuit below is acting up. Most of the time the 14s timer operates as expected, once in a while it stops early. I thought I could rely on the ESD diode at pin 2, but looks like that little spike is enough to cause problems.

Agree/Disagree?

[dmills]

Something odd with the U8-2 trace as I would expect the rising edge of 10m to cause it to shoot up from 5V to something higher, and I would expect the falling edge to cause it to go low before slowly ramping back to 5V.

Not what we are seeing.

Regards, Dan.