Repetier-Host Documentation – Troubleshooting

Connecting via Repetier-Server

Here you find detailed information how to connect Repetier-Host via Repetier-Server to the printer, which is recommendet.

Connection problems

One frequent problem at the beginning are problems with connecting to the printer. You should be aware of the three stages of the connection and first find out, at which stage your problem occurs.

  1. Select correct COM port. Only if you select the com port of your printer, you are able to connect, if no other program is connected to the printer (eg Repetier-Server). In the printer settings you have a dropdown list to select the port of your printer. These ports are only visible, if the printer is connected! So connect your printer and select the port. If you are not sure if it is the right port, unplug the printer and click on “Refresh Ports”. If the port vanishes for the dropdown list (the seleced port will not disappear, even if it is not available), you had the right port. You can of course also do it the other way around. If no new port appears, you need to install the driver first.
  2. Connect to the port. If the port is right, this will work. Having a connection does not mean, that you can communicate. It only means you are connected with the usb-serial converter of your printer board.
  3. Start communication. This is where most problems occur. Some boards like printrboard do not support reset over DTR signal. The reset is used to get a clean starting point, so we know firmware is ready to respond. If e.g. the connection was stopped in an error state (e.g. incomplete line, resend expected) you might get errors at the connection. In that case disable reset on connect, so the host does not have to wait for the start signal which will never come. After a successful reset the firmware will send a “start” to signal it is ready to receive commands, which is what the host waits for. If you do not get that or only some cryptic characters, your baud rate is set wrong. If you are using repetier-firmware you should be aware, that you need to use the firmware set in the eeprom, if that feature is enabled. That is the baudrate you had during your first installation. If you want a different speed, change it over the eeprom settings in the host. If you are not using Repetier-Firmware, set “Transfer Protocol” to autodetect or ASCII.

The host often shows some errors on the first connect. You can ignore them.

Connection problems during print

Most boards have in reality two connections between the firmware and the pc. The first one is the usb cable from your computer to the usb-serial converter on your board and the second is the serial connection between converter and processor. The baud rate has only an effect on the short path between the two chips. Nevertheless I had boards that worked error free with one baud rate and had every now and then errors with other speed settings. So if you experience errors during print, which are normally caught by the host, you should try to find a more reliable speed, since every error could go undetected or end in a not recoverable error. The other thing that often makes problems are usb cable. You should use shielded cable ferrit core, also this is no guarantee. In my collection of usb cable I have a 3m double shielded usb cable with gold contacts and as soon as I use it I get errors every 100 lines or so. Using a cheaper 5m cable on the same printer makes the connection error free. In some cases I even had a hang off the usb stack it self making the host stall. Only unpowering the printer completely allowed to get communication going again. These are problems, where the host has no influence on.

Crashes on startup

There are some cases, where the host will crash on startup. Possible reasons are:

  • Not .NET 3.5SP1 or .NET4 for newer versions installed.
  • Your computer has no OpenGL driver.
  • Not enough memory.
  • Operating system not supported. You need Windows XP or later or Linux with a recent mono version.
  • Invalid data in registry. Not sure how this can happen, but it has happened. Here you need to delete the registry data of the host, see “Configuration data”
  • Missing font Arial. Download fonts from Microsoft.

3D visualization not working

We use OpenGL through OpenTK library for showing 3d content. This requires OpenGL 1.5. For unknown reasons the library does for some card/driver combinations not select the driver and selects a generic driver from microsoft with OpenGL 1.1. Besides being slow it is unstable and does not work very stable. Often it helps to set graphic driver to full performance as shown in this video.
If you have a switchable graphics, select Repetier-Host to work with maximum performance in app.
Right mouse on the desktop, open switchable graphics, search repetier.exe and change it to maximum performance.

Last thing is check if in “Config – Preferences – 3D Visualization – General – Draw Method” was set according to your drivers capabilities. If in doubt set to “Autodetect Best” which uses the detected version to select best option..

Configuration data

Sometimes you want to store/restore some configuration settings. These are scattered a bit, depending on the parts concerned.

Host settings

The host settings are stored in the windows registry or for linux users, in the $HOME/.mono directory. In Windows press Win+R and enter regedit as command. You see the registry tree to the left and to the right the values for the selected key folder. The host stores all it’s data in HKEY_CURRENT_USER/Software/Repetier and it’s subfolders. If you have a good working configuration, you can export that tree in the editor. You can also delete the Repetier key folder and the host will create a fresh one on the next startup. If you have a custom host version, the path is named according to the printer vendor and you should reinstall the host after deleting the key.

Slic3r settings

Slic3r is a separate software included in the bundle. It stores all its configuration files in HOME/AppData/Roaming/Slic3r resp. $HOME/.slic3r for linux users. Be aware that AppData is set as invisible folder and you need to enable viewing ob invisible files in the file explorer to see it.