This happened to me as well and I tried reinstalling drivers/ repetier etc.

in the end it was as simple as going into printer settings and changing the baud rate to 250000
This may differ depending on how your board is setup but it worked for me!

My printer works fine with Repetier and I also see the 5 commands waiting when it connects. That is normal. The program sends several commands to connect and they are buffered until each one successfully processes.

Thanks, then I know thats's normal at least.

When I hit connect the printer reacts, and it says "Connected", but I get an error message in Repetier (see picture). Since this is a completely fresh install I'm now thinking it's the printer.
The strange thing is that after the re-install and the first connection to the printer Repetier tells me that there are 5 commands waiting.

I haven't set any temperatures or done anything at all and I'm therefore wondering whether Repetier tries to send some commands or if there are commands "stored" in the printer that is not executed yet.

You have to use 0022.  RH is buggy as crap on our machines.  What errors are you seeing in the log, if any?  Endstop hit?  Don't set it to run it over 208-212C ever.   Check your power connections if the lights flicker, if not check it anyway...if it looks loose fix it.  Check that all the cables are plugged all the way in. Cool the electronics [heatsinks and a case fan] (this should be done from factory, but isn't).  Other than that it should not just STOP.

I have gone thru connectors and all looks good.

I can't remember the exact message from the top of my head now and will have to test again, but Windows generates an error message when Repetier stops.
I'll see if I can get this again.

As mentioned previosly, the printer is working fine when I use Pronterface, or at least it has for the last 4 prints, and this tells me that there is nothing wrong with the printer or the computer, this is a problem with Repetier.

Lars-Inge wrote:

One thing I did notice it that it stopped heating the bed twice, it looked like it was just turned of. Couldn't see any error messages in Repetier.

Did it stop heating the bed during print, or after you had 2 unsuccessful prints?

in Repetier Printer Settings you can uncheck a box that says "Disable Heated Bed after Job/Kill"

It stopped heating during pre-heating, before I started the print.

The printer also stops during print...this is getting frustrating...

One thing I did notice it that it stopped heating the bed twice, it looked like it was just turned of. Couldn't see any error messages in Repetier.

Did it stop heating the bed during print, or after you had 2 unsuccessful prints?

in Repetier Printer Settings you can uncheck a box that says "Disable Heated Bed after Job/Kill"

I ended up un-installing all absolutely all software related to the printer, un-installing all USB-ports from device manager and then rebooting the computer.

After the reboot I installed Repetier Host again (0.82b) and now it's working...sort of. The first print stopped after a few minutes and the second one (same STL) stopped after a little longer time.
The third time it printed correctly.

One thing I did notice it that it stopped heating the bed twice, it looked like it was just turned of. Couldn't see any error messages in Repetier.

Make sure you have the correct Port selected.

I used my printer last evening and it worked fine, but this morning I can't get it to run. No changes are done on the computer (Windows 8) I'm using, and I have also tried on a different computer (Windows 7) with same result.

I can connect to the printer just fine, but I can't issue any commands to it. I get an error message at the bottom of the Repetier window (see attachment).
I get the same error when trying Pronterface.

I will obviosly send an e-mail to Solidoodle, but they are on a different timezone and I might get a quicker reply here...I hope... *S*

By the way, I have tried to upgrade the firmware, but I'm not able to using Arduino 0022. I get the same error message that a lot of people get:
- Binary sketch size: 49224 bytes (of a 63488 byte maximum)
- avrdude: stk500_getsync(): not in sync: resp=0x00
- avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51