HM 4.2.4 - Probes 3 & 4 weird behavior

[JWywal]

Hi all

So I just finished assembling my 2nd HM and plugged in the Rpi 5v to test. Configured the probe types in the interface.

With no probes plugged in - Probe 1 (TC) and Probe 2 are functioning as expected ('no pit detected' and 'off'); Probes 3 and 4 are reading temperatures.

Plugging in the TC probe and a TX-1001 in Probe 2 and the temps read almost the same.

Plugged in the same probe into probe 3, and the temp jumps up a bunch to an even more errant number, but strangely probe 4 also jumped up, with no probe plugged in. If I unplug 3 and switch it to 4, the same thing happens.

Plugged a probe into all four jacks and left it running for several hours. Eventually probes 3 and 4 settled down into a temp that was close (but still a few degrees off probes 1 and 2). Over time though, they still tended to jump around and then settle down.

For reference, here's a screencap of the graph over time:

http://imgur.com/xmrvhLe

Are probes 3 and 4 pooched? Should I try re-soldering the joints related to those two jacks?

Thanks!

 

[Frank Giacinto]

You can clean all of the joints with a toothbrush and rubbing alcohol, look at them under a magnifying glass and you will see the bad joints.

Or you can just resolder all of the joints associated with 3 and 4 not just the jacks, check all of the resistors also.

If you can post high resolution photos of the front and back of the board after you check your solder joints others can look and offer advise also.