Power On in axis freezes mouse and keboard.

This is a mazak m4 lathe with Ubunti 10.04 emc2 2.50.
This setup been running for about 8 years with the occasional mechanical wear issues.
A previous fellow employee refurbished this machine with linux as the controller.
All was good bar a month ago i replaced the motherboard battery as was loosing bios startup settings.
two settings in the bios where changed so no starting issues.
All starts fine and mouse and keyboard work well before turning on the cnc gear.
But lately the mouse and keyboard (usb) will freeze when clicking on the axis power icon.
i replaced the remote usb hub and its power supply and different mouse and keyboards no difference.
A mouse and keyboard directly into the computer at the rear of the lathe works sometimes but jittery and
sometimes the usb still locks up. Also once axis has started, and the mouse and keyboard are frozen, moving the machine by the jog joystick all the graphic on screen are working normal.
Running a cnc file there is no fault with machine or display. Only mouse and keyboard either frozen or very jittery.
oi are mesa cards via pp and serial for speed control.
Any pointers appreciated.. Doug

Another possibility suggested by the loss of USB connection when machine-on is activated is an electrical noise issue. You could check this by disabling all axis and spindle motor drives to see if the keyboard/mouse problem remains.

If its not electrical noise it may be something using most of your CPU time as Andy suggests.
You can test this by running LinuxCNC and then running "top" in a terminal window.

Thank you both for your replies.
I was thing noise from one of the io's or maybe cpu hogging.
I will be at this machine today and will update of any findings.

ps tried a wireless setup and can sometimes start the cnc side but still
have very jittery mouse/keyboard but when jogging thru the mesa cards all
jogs are true and screen display are good.
Doug

The jittery screen display but responsive jogging sounds to me like the real time thread is using up 95% of the CPU, not leaving enough for the non-realtime parts like the GUI.
It is possible some unintended program is gobbling up all the remaining CPU time, too.

Jon

I just had an issue with usb lately. I thought it was the power supply. It would freeze the screen but would continue to finish the file being cut.

I tried everything. I changed the computer for a dell I3 slapped in the hard drive from the old machine and everything worked fine. I still do not know what the problem is. But a new PC fixed it.

i got this on a Plasma and i added a PS/2 to usb adapter and all is gone well

Subscribed. I have / had this issue on one of my machines on rare occasion. It's just the USB keyboard shutting off after linuxcnc loads and the mouse stays on. I forget if plugging the keyboard back in brings it back to life. I'll have to pay attention to it next time it happens. This is on an old dell. Restart works and it does not repeat during machine run time.

Did this get resolved? I had a similar issue it was noise from a solenoid closing without a flyback diode. I found tracking the usb status with a command like: udevadm monitor --udev, I think was useful. I could actually see my usb microcontroller disconnect from the usb chain entirely and then reconnecting.

So in short, if you suspect usb issues combined with RF issues, you might be right, consider monitoring the usb services with udev or similar.

Sorry for super late reply but life got in the way.
It turned out that the problem was noise between the Boldar drive and the encoder.
We do not have another drive unit the same to test by replacement. The motor with encoder we don't have another to change.
The motor with encoder was replaced 10 months before this started.
Changed motherboard hoping pci bus problems as effecting usb mouse and graphics.
Turned out by rerouting the display cable away from the drive cabling stopped all problems.
So now the vesa and the usb extension cables are routed and all is well and stable.
I still have the issue of the generated noise which i will dig into when i can get to my cro's and sig generators.
Thanks to all advice