Jittery Probe

I have had some trouble with my second probe during cooks.

If you look at the image below I did this cook specifically to illustrate the problem with the probes. The probes were stuck in the meat very close together and you can see the blue one jumps all around initially before settling down with the working probe and then goes out of whack again.

It is not the actual probe as I have rotated through 3 probes I have. It is tied to the actual "port" that I am using.

My set up is the RD3 with the heatermeter. Everything else works fine. Blower, Servo, Pit TC probe and probe #1 as well as probe number 3 on my actual heatermeter which I use for air temp.

Any ideas or suggestions of further tests?

https://ibb.co/dfXsam

Check the resistors and capacitors for that probe. They might have cold solder joints and the RC filter might not be working due to that.

In addition to what steve said, you may want to wash the board in the area around those parts with some alcohol and a soft brush to get rid of excess flux. Make sure the board is fully dried before you plug it in...

Thanks for the help!

I am totally capable of washing with alcohol and a brush.

Should I be doing that with the RD3 Aux board or the heatermeter itself??

Also I'm a big novice here and although I do have a multimeter I would need a bit of guidance to check the resistors and capacitors. Any quick and dirty tips??

Thanks again!

Didnt realize you were using the RDTC board. Wash both. That also opens up the possibility of bad solder at either CAT5 jack or more likely the jumpers on your HM board, or even a bad CAT5 cable or ends.
Does the probe act funny when plugged directly into the HM?

I had four total probes laying around the house so tonight I plugged them all in to all of the ports and took notes

I had the RDTC plugged into about 35 feet of ethernet cable. I suppose I should redo the test with a different ethernet cable as I have a brand new 50 footer that I have been using.

Anyway the two I usually smoke with are listed as well as a brand new one just out of bag and one that the wifey uses for yogurt.

I haven't done cleaning yet with the boards.