Sticking Home/Limit Switches - Please help

So I have thought a lot about this, and I think I might know what the issue is.

My PicoPSU only has a 20 pin connector for the motherboard (instead of 24 pins)... I didnt anything of this becuase in all my years of building pcs I never had an issue.

But today I looked up what the extra 4 pins are: 0v, 12v, 5v & 3.3v

Maybe this is why the system is struggling, why when I set the direction signals to HIGH that the BOB can only give back 2v instead of the 3.3 it should.

There must be some wiring in the BOB which give the MB the same voltage it receives from it. If the MB was struggling to give the HIGH signal on multiple pins, then the BOB probably thought thats the voltage the MB operates at.

I have ordered a bigger (150w vs 80w) PicoPSU which comes with a 24 pin connector and will update this when it arrives tomorrow (thank you Amazon)

This is pure speculation, so if anyone has other ideas to test I would love to hear them.

Ok this Bob does not need the usb cable but it does need the 5v & 12-24v connected​ for it to work.
I have one of these and will set it up on Wednesday if you have not sorted it by then

ITS WORKING!

Finally, After weeks of going crazy (excluding the months of building it)!

So just for future reference, and so that hopefully, no-one has to go through this all as well, I will document the final diagnostics and then where and how I found the cure.

The replacement Motherboard PSU Arrived, I installed it and tested, but it only gave a 0.3v increase at the pins.
So I started to try to "Reverse Engineer" the board to see where this power was coming from. Everything on the board made perfect sense... there was nothing wrong with it.... Everything worked!

So I turned my attention to the Motherboard.

Changed all Bios Settings, Checked Solder on the Connector, Even did an LED and voltage test on the output pins...

Then I found the HAL Pin Test files... When I tried to test the input it was picking up nothing...

After a bit of research, I discovered that some Motherboards DO NOT have internal Pull Up Resistors on the Motherboard... leading to the exact symptoms I had (was looking at an old robotics site with a post from 2005 or something.
Tried to find information for my exact model, but couldn't find any reference to it and the parallel port.
I did find a model from the same range, but it suffered from a slightly different issue (inputs not detected at all - as opposed to active pin based input not working).

The solution, add pull up resistors to the BOB..
Bought some from Amazon, Soldered them on and IT WORKS.

So for some reason the problem was the board was only pulling up the pins to 2.something V
Now with the 2.2k Ohm resistors added it pulls it up to between 3.8 and 3.2 - enough to trigger the high state for the pin.

A Big thanks to PCW for helping adam3999 2 years ago in this thread...
It was the solution (to a slightly different problem)

NOW I can finally use the machine

Thanks for all you help, ideas and suggestions people!

Link to post forum.linuxcnc.org/18-computer/28929-no-...900m-onboard-parport

Glad you got this sorted. It is common practice to use pulups on input pins