Solutions to a few MC test failures

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1. Tests pre-dressing

2. Tests post-dressing

1. Tests pre-dressing

Check TDC status

Problem:

In the TDC display, red LED might be on.

Cause:

The TDCs might be wrongly configured 

Solution:

Reconfigure the TDCs

Go to the Startup page.

Click on the Configure MC button.

Select the TDC only option by clicking on the corresponding button.

Click on the Configure button

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 Test TDC crosstalk

Problem:

The first line (events) in the first table (bunch counter) contains zeros

Cause:

Reset has not been done properly

Solution:

Do the test a second time

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Test TRB switch

Problem:

The test fails for a TRB-PHI: the green light stays OFF

Cause:

The PN1 jumper has not been soldered during assembly: the jumper is open instead of being closed for the S- and S0 MC types

Solution:

Close the jumper PN1 by soldering it

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Test Snap and software reset  

NB: this test must be done after the TRB emulator test since it needs to have all BTIs properly configured. If the test has to be repeated, remember to run the TRB emulator test before.

Problem:

The test fails giving errors for a given TRB and BTI’s

Causes:

The BTIs might be wrongly configured.

OR

The voltage might be insufficient since the signals are sent to all the boards at the same time.

OR

The corresponding TRB is defective

Solutions:

1- Reconfigure the BTI’s

Go to the Start up page.

Click on the Configure MC button.

Select the BTI only option by clicking on the corresponding button.

Click on the Configure button

2- If that does not work: increase slightly the 5V

3- If nothing works, replace the corresponding TRB

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2. Tests post-dressing

Test crosstalk

Problem:

The test dead channel is not OK: some channels are below the number of triggers.

In RESULTS some green lights (group of 16: cell of 4x4) are off. For the MB3 MCs: the last group has only 8 lights (half board).

Cause:

A TP cable is defective

Solution:

Identify the TP cable, remove it and redo the test without the cable. If the cable has been correctly identified, replace it !

Test the defective cable with an ohmmeter to check if it is really broken.

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Test TRB TP

Problem:

The test fails.

Cause:

The PU clock delay has not been set correctly

Solution:

Go to the Minicrate Test/ calibration panel

Click on the PU timing test button

Activate the window and click on the Change PU button.

Put the value identified during the pre-dressing tests.

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