Strange Issues

Hi all,

I have had my machine working well for some time now, but am having a weird issue and hoping someone may be able to help me work out what I may have happening or may have done wrong.

Here is some background.
I'm was running 2 pci parellel port cards about year ago, then all of a  sudden it started playing up then stopped working. Worked out after some searching I had killed the pci card(s), so had a spare dual port pci card and put it in for it not to work for a bit/pick it up using lspci -vv command, but then managed to get it to work somehow, carnt remember how but anyway.

So there is the background, now to my really part.
I went to do some tweeking last night, pluged everything in as normal, then fired up linuxcnc (V2.7.xx) and this is where i lost my mind, the machine tried to take off in a strange direction make a heck of a noise, estop did not work so had to pull a power plug to kill it.

Upon further "playing/research" I found everything seems to be ok and all untill I open linuxcnc which is when the machine does it weird stuff.

What I'm woundering is has anyone had this happen before, or able to point me in the direction of anything else to try or loom for to see if i can fix this. I'm also woundering if thea software or hardware issue, as like i said its only once i open linuxcnc this happens, so wound have thought if its the pci card it would either not work or do its weird stuff instatly.

Hope the question make sence and someone is able to help point me in the right dirextion of what to try to fix this, I will jave a new pci card on the way in a few days to see if thats the issue but not wanting to kill it right away if I can help it if it is that that I have killed.

Thanks all.

Use a grounded 3 prong plug/cable for the PC.
Lack of grounding will do that.

Thanks tommylight.

Im sure if im correct that i already have 3 prong grounded cables on my pc but i will check and see at some point, change if i need to and go from there.

Hello again.

I managed to fix this issue somehow, i checked the grounds on everything and that didn't seam to do much, then changed my db25 cables over and that kinda worked to moved the card between the 2 pci slots for about 2 hours trying things and playing with bios settings and now it seams to be working great.

So I think the pc just got outta synch or something, but I now occasionally have one of my axis flip it direction and go in reverse after a power down, no biggy just need to change the invert sig in the *.hal file, but this is a little annoying, so does anyone know how to stop this happening??

Cheers

I think this can be electronic noice, do you know this document?

linuxcnc.org/docs/2.8/html/integrator/wiring.html