Inspecting the monitor pcb again, I found this smd cap showing a sign of stress. No short across it.

 

Hi Mr Chips
Checking in with you. Did you get a chance to see the results I shared post 10 Ohm 3W load?

After I loaded the 5v rail with the resistor connected in // to CN1 pins 3 & 9, pins 1 and 2 read 25 volts. Pin 3 and 4 read 5 volts.

https://www.allen-heath.com/media/xone_db4_db2_004_066_psu_2.pdf

 

This is what we suspected.
Something is wrong with the SMPS. I don't know what it is. I will have to look over the circuit schematic.

 

CN1 voltages when pin 9 loaded with 10 ohm 3 w resistor.

 

So how did it end? Did you manage to find the problem?

 

It ended up being a motherboard issue.
I purchased a brand new motherboard, plugged it in and the mixer analogue inputs came back to life.
I still have the damaged motherboard but I am not sure which component went bad. I purchased the motherboard from this website:

https://sbsav.co.uk/shop/spare-part...-xone-db4-motherboard-main-board-004-067.html

 

Hello,
I need help.
I would like to replace the Xone DB4 Eq LED rotary potentiometer. Where can I order this type, or what type is it? Thanks for the reply