Hello Michael
I'm not sure I understand what you did : were the DC plugged or not when you measure 24 V on Vin+ ? And 2.7 V was it
on Vout+ ?
The 3 jumpers act as switches for the 3 DC. When they are set, the output of the DC supply the board. When they are open, the down stream modules are not supplied. So it is better to let them open while testing, there is less risk to damage something else.
Is your INA U5 plugged or welded ? If plugged,testing is easy but if it is welded, you may try first to bridge it (between Vin 24V and Vout 24V, 2nd and 3rd pin starting from the top) . Be cautious, not to touch the other pin !!
When reading again your 1st post, do you suspect something on the capacitor (blauen Dinger) . To be sure, you unweld one and then plug the corresponding module. Same to test the 1000µF, the easier is also to unweld it and make the test.
The capacitors are there to smooth the voltage, but there is no risk to test without them if your source is a battery. Just keep the 3 jumpers (1, 10, 11) open.
Viel Erfolg