Siegfried Loeffler

I bought this macbook on ebay as a replacement for my other 13' unibody - i have no information about its history. It...

I experienced the same problem on a 2019 iMac Retina 27”: Fans always on at full speed, SMC and NVRAM resets didn’t fix it. Booting with D key pressed into diagnostics tool came up with the message indicating I might have a fan problem (ah really?) and error code PPF003. Reading your description I realized the connector might be the issue. So I just took my flat hand and tapped several times on the back of the iMac. Problem solved - no more fan noise! Thanks so much, you saved me from having to send it back to an Apple Store !

It was sold as working "partly"(i.e. only on external power supply), which is perfectly true. The seller had acquired in a batch and doesnt know the history that's why I am asking if somebody could identify this might have been a liquid spill damage. I believe it should be repairable, given the main components all seem to work well (machine boots and works under external PSU and Apple Hardware Diagnostic finds no fault). Having listened to Louis YouTube seminars and being an electrical engineer, I am up to take the "brain challenge" of analysing and trying to repair this beast. Now... need some help to the above questions, in particular identifying where the charging current sensing stuff (R7020, R7021, R7023) are located...