1301. No response or control on any shimming gradients.
- Verify the shim coil cable is connected tightly to the console and to the
shim coil.
- Verify the power supply is on and normal, power supply LEDs are on.
- Make sure the system can setup and get a locked lock signal.
- If steps 1 through 3 check okay:
- For XL, VXR, GEMINI and UNITY systems:
The Auto DAC Board and/or the Shim Offset Controller Board may be
defective.
- For MERCURY systems:
The Shim DAC Driver Board may be defective.
- For UNITYplus and INOVA sytems:
The Shim CPU Board and Z0/Z1 Driver Board may be defective.
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.
- There may be a short in the shim coil and/or the shim coil cable.
- The Shim Offset Controller Board or Auto DAC Board may be defective.
1304. A big hump on one side of the lineshape.
- Check for any metal objects sticking to the magnet, or inside the bore of
the magnet.
- Make sure that the spinning gradients are not out of range.
- If they are out of range, It is possible that one of the cryo shims in
the magnet has quenched.
- If spinning gradients are not out of range, turn Z3 or Z4 to opposite
positions of the dial and see if the hump has moves or disappears.
- 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.
- Make sure this is not a shimming problem.
- Is there any response from the shimming device, mouse or knob?
- If there is response, check the spinner, spin rate, or scoring on the
sample tube.
- If there is no response:
- XL, VXR, GEMINI and UNITY systems:
The Auto DAC board and/or the Shim Offset Controller board may be
defective.
- MERCURY systems:
The Shim DAC Driver Board may be defective.
- UNITYplus and INOVA sytems:
The Shim CPU Board and Shim/DAC Driver Board may be defective.
1307. Ringing on the base of the lineshape.
- Verify that this is not caused by air line pressure that is set too high
or too high a bearing air pressure setting.
- Ringing may be an indication that the Crystal Oscillator is oscillating:
- XL, VXR, UNITY systems:
Check or replace the Crystal Oscillator.
- GEMINI systems:
Check or replace the Master Clock Board.
- UNITYplus and INOVA systems:
Check or replace the Reference Generator Board.
- MERCURY systems:
Check or replace the Junction Board.
1308. Z0 is always shifting back and forth. (UNITYplus and INOVA systems
only)
- Verify that the external environment is normal including room temperature,
air line stability for both the system, and the anit-vibration legs.
- This may be an indication of a defective Z0/Z1 Driver board.
1309. Some of the non spin gradients are very sensitive.
- Check for a short in the shim coil and/or the shim coil cable.
- The Shim Offset Controller board or Auto DAC board may be defective.