Beam Stop/Collimator badly aligned

If you knock the beamstop/collimator you will hopefully be able to recover by just pulling the G-ring assembly towards yourself on it's supporting mount or if that alone doesn't work by adjusting the 'bstopz' and 'bstopy' motor in mxCuBE : use the expert mode,  and taking another image. For more information on aligning the beamstop see the backstop/collimator page.

Cannot move the light in


1- Check in spec(exp) if the diffractometer is locked, you can unlocked it with the command SCMinidiffGetControl.

2- Check that the Wago device servers which control the backlight is running either with the dserevr application or :

  • ssh device server computer (see below for user/passwd)
    Beamline Computer
    14-4 lid144
    23-1 lid232
    23-2 lid233
    29 lid292
  • Kill the server by typing bliss_dserver stop Wagods
  • Restart the server by typing bliss_dserver start Wagods
  • A second device server (called WagoCt) is linked to the WagoDS to read and calculate the flux , it should be restarted by typing bliss_dserver restart WagoCt or with the dserver application on the control PC.
  • Type reconfig in spec session.

Phi Control lost

The phi axis doesn't spin during the data collection (with an error in spec session) or the crystal does not turn when you do your sample centering.

1. Try to type in the spec(exp) session, phi_init. This command will send the phi to search for the home position (phi should spin then, check with the camera) and restart the device server controlling the rotation axis.

2. If the problem persists (for local contact only, for BL with a minidiff like ID23-1 and ID23-2): you may need to take drastic action like turning the galil controller off/on as there is still functional problem with the controller which is being investigated. The galil controller is located at the in one of blue racks associated with each beamline, see picture below. Before you do anything, check the light status, in normal operation the lights are all green.

Galil carda Galil LEDs


The bottom light should always be green, if it is red then check the air pressure gauge on the back of the mini-diff in the experimental hutch, see picture later.If the air pressure light is green then try switching the controller off/on. The controller can only be turned off from the back. So you need to go round the back and switch the controller off and on from behind (large orange switch). PLEASE TAKE CARE WHEN DOING THIS. Then use the command phi_int to restart the softwares.

Please note in the logbook if any of the lights are red.

If the air pressure light is red and the air pressure gauge at the back of the mini-diff (side nearest the slits) is below 10 bar then the controller will stop as the spindle axis can be damaged at lower air pressures. If this is the case, the booster unit supplying high-pressure air may have failed. The local contact will know where the booster is and can check this. If it is the booster, instructions are stuck on each booster showing how to bypass it and use an alternative booster. Please make sure you inform the technical staff that a booster has failed.

Air press


Only see black image instead of sample in mxCuBE

You only see black in the sample window for crystal centering. You should always see somthing in the sample window. Put the light in and rise up the light level (should be above 0.5 at zoom 1). You can move the beamstop out. If they are still nothing, then try restarting the video device server (Prosilica device server : bliss_dserver stop Prosilica /bliss_dserver start Prosilica in BL control computer shell).

It is possible, but rare, that the backlight has been badly knocked. So if you still don't see anything it's a good idea to get a torch or use the extra fibre-optic cord (should find it around the light source) to shine a light directly at the camera.


Minidiff fuse

These have to be changed by an expert (technican or local contact). To change the fuse you first need to turn off the power, you'll find the power switch at the back. Then unscrew the hook at the top of the mini-diff and remove the cover. You will then see three fuses at the side - picture below:


You need to unscrew the knob and change the fuse. Then replace the cover, power on the mini-diff and restart the device servers:

Recalibrating the zoom

Occasionally the zoom motor will lose steps and you cannot zoom out enough to see your crystal. In the lowest zoom, (1), you should be able to see almost all the YAG screen. If this is not the case then simply recalibrate the zoom by typing zoom_init in spec(exp).


Additionally if the correction to be applied to get a proper crystal centring is too large and may lead the motor above the limits, the correction won't be applied. So please check first if the magnetic base is well mounted on the phi axis or if the pin is properly mounted on its base (if it is bent, we may be not able to apply the proper correction as the motors have only few mm range of movement).

If you feel it could be due to motor problem (position lost, etc...), you can reinitialize the motor positions by running "minidiff_init sampy" and "minidiff_init sampx" in spec(exp) session.



Device server login is blissadm