LCU troubles and solutions

When no FOCAS status could be obtained from UI (e.g., every button is in yellow or red), and it would not be recovered even after restarting softwares, a LCU might be in trouble.

• Note: This trouble is very rare. Trouble in communications within FALCON softwares (CD, CE, UI, etc.) is the cause of the trouble in many cases. So first try resetting the software before resetting the LCU.

Check the cause:

Exit CD, and issue "btest" command on a unix prompt from a focas2 terminal. Type in the board number with a possible problem. If message "ANSWER: AK??" is returned, it is okay. No answer is returned in case of LCU error.

Caution: Sometimes a part dose not move even though "btest" returns normal answers. Try also the solution below in such cases.

Solution:

1. Go to FOCAS in the dome, and open the main VME box of FOCAS.
2. Take off the electric connector of LCU (Gray color common to all LCU connectors, located on the right side.) and insert it back after a while.
3. If it does not work, check if the white connector between LCU and the cable extending from the multi-serial connector of FOCAS2 is correctly connected.
4. If it still does not work, LCU needs to be replaced.

• Note: Replacing the LCU board needs some time (~1h). Ask SA for the help if you need to do that.

Replacing LCU