Probe 0 always reads 60


 

AWedmore

New member
Hi, I just finished building my TC HM 4.3 and my Probe 0 is always bouncing between 60-62 degrees, even with no TC attached. When I attach the TC, there's no change in temp. I even de-soldered my TC and still got the same readings. Any ideas? I'm at a loss...



 
When I zoom in it gets a bit blurry and has a somewhat indirect viewpoint, looks like the 0.1u capacitor below the TC amp IC has something odd going on, might want to check that.

Below is a chart I made to troubleshoot the TC circuit on the aux thermocouple board, the part locations are different but the components are mainly the same as the board you are working on. The board below has a couple extra parts for a reference offset adjustment but should still be helpful to check for shorts between adjacent IC legs and connection to the other components.

RDTCv6.3-14.jpg
 
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