1301. No response or control on any shimming gradients.

  1. Verify the shim coil cable is connected tightly to the console and to the shim coil.

     

  2. Verify the power supply is on and normal, power supply LEDs are on.

     

  3. Make sure the system can setup and get a locked lock signal.

     

  4. If steps 1 through 3 check okay:

     

1302. No response or cannot shim on one of the five knobs. (AutoXL, VXR, GEMINI systems only).

This is an indication that the particular knob or Knobs Interface board may be defective.

1303. Z3 and Z4 are very sensitive.

  1. There may be a short in the shim coil and/or the shim coil cable.

     

  2. The Shim Offset Controller Board or Auto DAC Board may be defective.

1304. A big hump on one side of the lineshape.

  1. Check for any metal objects sticking to the magnet, or inside the bore of the magnet.

     

  2. Make sure that the spinning gradients are not out of range.

     

  3. The Shim Offset Controller Board or Auto DAC Board may be defective.

    For more information on shimming please see Basic shimming techniques.

1305. The lock signal is locking negative instead of positive.

This indicates that the magnet field is up with a reverse polarity with respective to the system. Switch the 0/90 Degree Switch located on the console Lock Receiver board to the opposite position.

1306. Cannot get rid of the sidebands.

  1. Make sure this is not a shimming problem.

     

  2. Is there any response from the shimming device, mouse or knob?

1307. Ringing on the base of the lineshape.

  1. Verify that this is not caused by air line pressure that is set too high or too high a bearing air pressure setting.

     

  2. Ringing may be an indication that the Crystal Oscillator is oscillating:

1308. Z0 is always shifting back and forth. (UNITYplus and INOVA systems only)

  1. Verify that the external environment is normal including room temperature, air line stability for both the system, and the anit-vibration legs.

     

  2. This may be an indication of a defective Z0/Z1 Driver board.

1309. Some of the non spin gradients are very sensitive.

  1. Check for a short in the shim coil and/or the shim coil cable.

     

  2. The Shim Offset Controller board or Auto DAC board may be defective.