Is it connected to the scope? If so it is a 1 or 10 Mohm input. That might be sufficient to pull an input low (or high).

Oh - and you may want to disconnect the cables and just watch the reset line. If it returns to resetting - you'll know that the issue is CPU (power supply or similar) issue - but if the line switches - it is a schmitt trigger issue.

Peppersass wrote:I do think there's a chance that you inadvertently fixed a cold solder joint when you attached the leads. Cold solder joints can cause all sorts of random symptoms, including intermittent voltage sags. Could be just a tad of temperature increase/decrease or vibration that makes it happen.

Agreed.

Fingers crossed that this is indeed the case.

AssafL wrote:Is it connected to the scope? If so it is a 1 or 10 Mohm input. That might be sufficient to pull an input low (or high).

Negative. Just 6" lengths of 22ga jumper wire.

AssafL wrote:Oh - and you may want to disconnect the cables and just watch the reset line. If it returns to resetting - you'll know that the issue is CPU (power supply or similar) issue - but if the line switches - it is a schmitt trigger issue.

Good call. The reset line can be watched through the ATE connector, without using any test points. I'll pull the test leads when I get a chance and see what happens.

Cheers!

- Jake

Jake_G wrote: Negative. Just 6" lengths of 22ga jumper wire.

A resistance is far more likely to stabilize something than the reactance of a short pigtail. (Except at RF)

Not that its 100% impossible, just 99.9% unlikely.

So I'd suspect a cold solder joint. BTW - it may be that the cold solder joint is altogether elsewhere and the constant jostling of the board scraped away a bit of corrosion. If that is the case, the issue will return. maybe wiggling the board can get it to reboot?