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Re: HVAC issue

Posted: Mon Jan 08, 2024 7:47 am
by Tom
Yes, it's 47uF (25v or higher). But be sure to check the part you remove, as there were more variations of these boards than I previously realized. It should be marked. The capacitor is polarized, and most replacements will have a black stripe or other marking to shew the negative (ground) side. The datasheet with part numbers for the 4201A is in post #9 of the thread you linked. That chip is the servo driver that makes the motors turn just enough to match the slider and other inputs. That linked thread has the theory of operation detailed showing how they work to turn the motors exactly to the point needed. (I have lots of those chips if needed, somewhere....)