Hi all.
I built the HM 4.2.4 without thermocouple support and afterwards decided to switch to thermocouple support. So I got the parts (thanks Peter F), desoldered R18 and the pit jack and soldered the TC parts. I did the testing for shorts and connections which was ok. I applied power and connected a thermocouple (once I received one from China), configured it in the UI, but it still shows - No Pit Probe -
Now I did measure the voltage at 4 (w/o having a probe connected): it is something like 0.1mV and not 3.2V - 0,1V as suggested. What I observed while measuring: If I put the measurement tip at 4, the display shows 2 degrees C. The display also reacts, if I short TC- and TC+ with my finger (jumping from 0C to 12C or so).
Then I bought some isopropyl and cleaned the TC area with a toothbrush, as suggested in other threads, but it still does not read 3.2V at 4.
Do you have any suggestions on how to proceed?
Any help would be appreciated.
Photo: https://goo.gl/photos/veQRz8NibYGUn54E7
I'm not able to post a image (new user restriction, I guess).
I built the HM 4.2.4 without thermocouple support and afterwards decided to switch to thermocouple support. So I got the parts (thanks Peter F), desoldered R18 and the pit jack and soldered the TC parts. I did the testing for shorts and connections which was ok. I applied power and connected a thermocouple (once I received one from China), configured it in the UI, but it still shows - No Pit Probe -
Now I did measure the voltage at 4 (w/o having a probe connected): it is something like 0.1mV and not 3.2V - 0,1V as suggested. What I observed while measuring: If I put the measurement tip at 4, the display shows 2 degrees C. The display also reacts, if I short TC- and TC+ with my finger (jumping from 0C to 12C or so).
Then I bought some isopropyl and cleaned the TC area with a toothbrush, as suggested in other threads, but it still does not read 3.2V at 4.
Do you have any suggestions on how to proceed?
Any help would be appreciated.
Photo: https://goo.gl/photos/veQRz8NibYGUn54E7
I'm not able to post a image (new user restriction, I guess).
Last edited:
