Mac pro 3.1 no chime all fans run

Hi I have just recently acquired a mac pro 3.1 Model A1186 EMC2180 that wont start.

I have measured all voltages from the PSU which all appear to be fine.

Diag lights always show STBY and when the white light on front lights up will briefly flash GPU and then shows EFI.

I have removed both memory board, all hard drives and DVD drive, Graphics card and then removed all fans which did run, there also was a very small BT card which was removed Front panel USB disconnected as well as the FireWire port.

I have noticed when plugging in a K/B you can not press get caps lock or num lock lights to work however there is power on the ports confirmed by charging devices but wont charge an iphone.

When first plugging in to 230v the OT_A and OT_B quickly flash which is normal.

Any thoughts on what to do next