Power switch HP ENVY 795 desktop

[Cancelled_2023]

Hello All,

I was wondering if anyone here could help me with the HP ENVY 795 Motherboard (BERKS) and the power switch. 

I am using this MB in a home built configuration without the original case and wiring and hence I am missing the power button and the HD activity LEDs and power ON LED.    I was unable to find a replacement switch anywhere.  So if anybody has some info on the actual part number / can take a photo of the switch board or even could provide me with a schematic it would be extremely helpful.  

The MB has a 4 pin strip connector (5th missing) for the power.

In stand by : 

Pin 1 is ground,

Pin 2 is 20 ohms to ground and at 0 V in stand by,

Pin 3 is 3.7V,

pin 4 is 0V.

I have found out that when you connect pin 2 and 3 briefly, the system powers up.

When powered on,  pin 2 goes to 3.7V and pin 4 goes to 5.5V. 

I need to connect a scope to the pins to work out if they are DC or signals e.g. HDD activity or other.

So far it seems to work, but in 'normal operation in a PC one can do a forced shutdown by holding the power on button for 10-20s? 

I haven't tried this yet since I don't know if my my lash-up is correct and shorting pins 2 and 3 for longer (like pressing the button for 10-20s) is OK for the system.  

Thanks for your help.