Screen current was not responding

Issue

Screen current was stuck at 285nA.

Environment

Titan Cubed G2 60-300

Resolution

These are possible resolutions for the issue:

• Issue was fixed after removing and re-installing Fluscreen

Cause

These are possible causes for the issue:

• Possibly charging on Fluscreen.

Details

Troubleshooting actions done to find the root cause:

• Close column valves and then measure the voltage between SCA X15 and X1. Also check the displayed screen current.
• On SCA, place jumper on W1. Measure the voltage between SCA X15 and X1. Also check the displayed screen current. (Expected voltage is ~2V)
• On SCA, place jumper on W2. Measure the voltage between SCA X15 and X1. Also check the displayed screen current. (Expected voltage is ~7.8V)
• Place jumper back to W3 when done.

By setting the jumpers on SCA, we will get a fixed output value as it is not influenced by the current on the Fluscreen. Therefore this can give us an idea of the problem is from the input or output of SCA.

For this particular case the output value is correct, so this means the problem is caused from the input between Fluscreen and SCA. Hence FSE has to check the Fluscreen cable, feedthrough, etc. Issue was solved after FSE removed and reinstalled the Fluscreen.