The ants come marching in (and release magic smoke)

This doesn't have anything to do with an Arduino, but I am wondering if anyone has a theory about what happened to the circuit board on my dishwasher. The writeup is here: https://sites.google.com/site/boschdishwasherrepair

Basically, it appears that ants shorted out pins on a microprocessor causing a major current surge and melting the solder off a large current carrying lead (not sure the exact component). Can the body of an ant carry enough voltage to short circuit a microprocessor? Thoughts? Comments?

Dan

Well, first capture an ant and get out your ohmmeter... :smiley:

When a large amount of current goes through the ant, it would fry and not conduct, methinks.

Of course, I don't know for sure.

Bugs do all kinds of things to boards I fix about 50 boards a year in stoves, dish washer and microwaves. And bugs are the number one killer. That and the fact that most newer stuff is made poorly.

I think that "things made poorly" is more accurate. nothing is really tested anymore or for that matter well inspected if at all. It's all based on 'acceptable failure' today, methinks...

Bob

Well what i see is poorly made boards plus a bug or two and things start to fell. The bad soldering show up I've pulled power transistor off a board the solder not even holding them. buttons the same thing. Reflow the board and it works like new. It't just poorly made stuff now days.

Maybe the ant bridged the pins and died causing a faulty input/output logic that caused the high power device to be powered to long, overheat and melt solder. It could also have been dead some time but damp air absorbed into it's body made it conduct.
I have seen a working PC stored in the loft for a few weeks fail to boot properly when removed and powered on. The accumulated dust on the internals was fine when PC was used daily (probably overheated the thing slightly) but storage in the loft had allowed the dust to get damp and cause problems. A quick vacuum out and it started working again.

Hi,
'Electric Ants' are a real and can cause a fair bit of trouble. For some reason they are drawn to electricity -

Notice the date is 2nd August, not April 1st

Duane B

rcarduino.blogspot.com

Grace Hopper discovered the first computer bug, BTW.


http://www.anomalies-unlimited.com/Science/Grace%20Hooper.html

Riva:
Maybe the ant bridged the pins and died causing a faulty input/output logic that caused the high power device to be powered to long, overheat and melt solder. It could also have been dead some time but damp air absorbed into it's body made it conduct.
I have seen a working PC stored in the loft for a few weeks fail to boot properly when removed and powered on. The accumulated dust on the internals was fine when PC was used daily (probably overheated the thing slightly) but storage in the loft had allowed the dust to get damp and cause problems. A quick vacuum out and it started working again.

This is what I suspected - logic problem leading to overcurrent of a high power component. I hadn't thought of absorption of moisture, but that is probably what happened. It seems like the ant have been in there a while since it is winter now, and I haven't seen any ants for months. We did have a major ant problem in the summer.

Perhaps an ant farm shield would make a good organic random number generator project.

-br

It's the superconducting ant spit that does it...

I had a heck of a time with the fire ants getting into my stuff. They would crawl into the contactors for the AC compressors and jam in so tight the relay would quit working. You'd have to dig them out with a screwdriver. I solved that problem by getting hermetically sealed (= expensive) units. I had the same problem with some outdoor light switches.

I don't know what their fatal attraction with electricity is all about. :slight_smile:

I would pay to find something the ants in my house could be fatally attracted to.

Duane B

The ant by the SOIC 8 is sitting between the source and drain that handles the switching of the AC in the transformer.

About 20 years ago a very expensive spectrophotometer in my lab started behaving erratically. I finally tracked the problem down to a cockroach impaled on a circuit board who waved his legs against the board stacked above it. It doesn't take much conductivity to make digital electronics misbehave. Ciao, Lenny

The places the ants were stuck has nothing to do with the problem at all. That solder joint got cold over time (thermal expansion and contracting) over time which leads to a failed solder joint like that. Also if the component soldered in that joint has some mass, the vibration from you opening and closing of the door makes it shake loose over time, rendering you with the same problem.

This time it was not the fault of the bugs...

// Per.

It may also have touched the metal casing? Looks like a high-current discharge caused the blackening. The leads on that
board have not been cropped short, i.e. poor build quality. Ants are usually associated with high voltage flashover in the mains
section of an appliance - they are one reason why mains wiring should never run close to sensitive low-voltage circuitry!

fungus:
It's the superconducting ant spit that does it...

ANTimatter...

Of course they're electromagnetic....ANTennas.