Cant stress enough how i have tried everything!! , I have got to the point were i stripped it down to the bare motherboard. This still shows no sign of life and can not find voltage anywhere on the MOBO ( except for the odd 0.2v) I have tested the power adapter (All 5 of them!) so I know its not that. With this particular model the DC power jack is soldered directly to the board. Searched the internet for hours but there is no videos diagnosing these type of PC. I have tested the CMOS battery removed all addition parts ran a multi meter over the board but doesn't show any sign of life. Here is a link to the model if anyone has worked on one of these before some help would be really appreciated.
HP Pavilion All-in-One - 23-q103na (Touch) https://support.hp.com/gb-en/document/c04649561
One thing to note is the adapter no matter what one starts to beep only when plugged into this particular motherboard. figured there is a short or something overloading it thats making it drop power.
Someone please help ! :)