My home humidifier has been acting strangely, giving me false high readings. I did an initial check and the humidistat mini-board was not getting the required 5VDC and the output frequency was therefore too low. So I looked upstream and tried to figure out where my voltage drop was. I was only getting 3.3VDC going into the 5VDC voltage regulator. I pulled off each of the non-SMD components and checked them. C1 checked in a 2.2uF (this is a 250VDC cap). R7 was 47ohm. R10 was 10ohm. C2 was 1000uF. While I had C1 off, I check R9 and it was 330kohm.
Also note that I'm not sure about the polarity and value of C4. There are 2 polarized caps on this board, C2 and either C4 or C5 (not shown).
When I plug this into my home wall power, I get 128VAC across ACL and ACN. I get a 120V drop across R9. I get a 6V drop across R10.
What could be wrong with this system?
Also note that I'm not sure about the polarity and value of C4. There are 2 polarized caps on this board, C2 and either C4 or C5 (not shown).
When I plug this into my home wall power, I get 128VAC across ACL and ACN. I get a 120V drop across R9. I get a 6V drop across R10.
What could be wrong with this system?
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