I purchased a Solidoodle 3 printer a while back, used it a bit then put it aside for about a year. When I got it back out I could move X Y Z and extrude manually (from the manual control panel). However, when I sliced an STL file and printed it, the extruder head would move X and Y and the table would move in Z, but it was not extruding any plastic. I could see extrusion commands in the G-code, but nothing was coming out.

I contacted Soldioodle support and they responded pretty quickly with what I think are standard responses - check this, check that, etc. I installed the serial driver, got an error message that it may not have installed properly so had it do it over. Still no printing extrusion.

I re-installed Repetier Host - and now I had a duplicate list of printers. Selecting the correct one, I was still able to move everything and extrude manually, but no extrusion while printing.

I uninstalled and re-installed everything (still have the duplicate list of printers) and now it will not even move. Tried it on a different computer, no movement.

I then noticed that on the Manual Control Panel there were messages like "4 commands waiting", and if I tried to move something from the Manual Control Panel the number of commands would increase.

These are the commands on the log:

16:44:07.055 : OpenGL renderer:NVS 3100M/PCIe/SSE2
16:44:07.055 : Using fast VBOs for rendering is possible
16:44:17.085 : Serial com error:System.IO.Ports.SerialErrorReceivedEventArgs
16:44:17.090 : Serial com error:System.IO.Ports.SerialErrorReceivedEventArgs
16:44:17.091 : Serial com error:System.IO.Ports.SerialErrorReceivedEventArgs
16:44:17.099 : Serial com error:System.IO.Ports.SerialErrorReceivedEventArgs

Obviously there is an IO problem but I have no clue on how to solve it.
I used Windows 7 device manager and removed the USB serial interface and re-installed it (by connecting the printer) but still no movement.

I can hear a "clunk" kind of sound whenever I connect the USB cable, and the red light on the printer mother board will light (and is steady) when the USB is connected with or without the main power being connected.

Anyone have any suggestions?

Thanks
Jeff