1. A Low Voltage Problem Seen by TMB Greg Rakness University of California, Los Angeles CSC Operations + DPG Meeting 28 July 2010

2. Intermittent Communication Problems with some TMB’s “The problem which we met on ME+1/3/28 chamber now showed up for ME-1/1/29. After a new TMB firmware was downloaded, the TMB of ME-1/1/29 lost VME configuration and stopped working. We tried 2 new TMBs on this slot, but all of them showed the same symptoms: 1.“After power up a crate the TMB is OK, 3.3 V is about 3.13 V current 2.4 A. 2.“Then slowly the 3.3 V dropped to the level when TMB refuses to work. For some TMBs the limit is around 3.05 V. 3.“Power cycling the crate always brings the TMB in the working state but then it died. “We have a few such TMBs in the system which show the same behavior, for example ME+1/3/28, ME+4/1/05.” To be explicit: “TMB… lost VME configuration” means unable to communicate with this TMB… 28 July 2010G. Rakness (UCLA) 2 CSC Elog 422012 by M. Ignatenko (UCLA)

3. New Button Created on “Expert Tools Page” (accessible from “Yellow Page”) 28 July 2010G. Rakness (UCLA)3 Loop over all TMB’s to extract voltages from on-board ADC’s…

4. Communication Voltage at TMB 4 ME+ ME  When the voltage on the 3.3V-line is outside of specification (±5%), proper communication with TMB is not guaranteed… NB: average current on 3.3V-line = 2.4A Spec = (3.3V ± 5%)  44 TMB’s at p5 have voltage on the 3.3V-line below specification… 3.3V-line voltage measured on-board TMB (Volts) Number of TMB’s 28 July 2010G. Rakness (UCLA) 2010 July 27 ~15h00

5. ME+ endcap: 21 TMB’s with 3.3V-line < 3.135V +--------------+--------------+--------------+--------------+--------------+--------------+ | station | crate | ring | chamber | slot | measured V | +--------------+--------------+--------------+--------------+--------------+--------------+ | 1. | 5. | 1. | 14. | 6. | 3.12 | | 1. | 5. | 2. | 13. | 10. | 3.11 | | 1. | 5. | 2. | 14. | 14. | 3.12 | | 1. | 5. | 3. | 12. | 16. | 3.11 | | 1. | 9. | 3. | 25. | 18. | 3.13 | | 1. | 10. | 1. | 27. | 2. | 3.1 | | 1. | 10. | 1. | 28. | 4. | 3.13 | | 1. | 10. | 1. | 29. | 6. | 3.05 | | 1. | 10. | 2. | 27. | 8. | 3.11 | | 1. | 10. | 2. | 28. | 10. | 3.09 | | 1. | 10. | 2. | 29. | 14. | 3.13 | | 1. | 10. | 3. | 27. | 16. | 3.09 | | 1. | 10. | 3. | 28. | 18. | 2.98 |  Misha observation | 1. | 11. | 3. | 30. | 16. | 3.07 | | 2. | 3. | 2. | 17. | 14. | 3.12 | | 2. | 3. | 2. | 18. | 16. | 3.13 | | 2. | 4. | 2. | 26. | 20. | 3.11 | | 2. | 5. | 2. | 27. | 8. | 3.12 | | 3. | 6. | 1. | 17. | 2. | 3.13 | | 4. | 2. | 1. | 5. | 2. | 3.02 |  Misha observation | 4. | 2. | 2. | 12. | 16. | 3.12 | +--------------+--------------+--------------+--------------+--------------+--------------+ 28 July 2010G. Rakness (UCLA) 5  Some crates have multiple TMB’s with 3.3V-line below spec  Some crates have only one TMB with 3.3V-line below spec  Disproportionate number of problems in station 1 (?)

6. ME  endcap: 23 TMB’s with 3.3V-line < 3.135V +--------------+--------------+--------------+--------------+--------------+--------------+ | station | crate | ring | chamber | slot | measured V | +--------------+--------------+--------------+--------------+--------------+--------------+ | 1. | 3. | 3. | 7. | 18. | 3.1 | | 1. | 4. | 2. | 9. | 8. | 3.13 | | 1. | 6. | 1. | 15. | 2. |INCOMMUNICADO | | 1. | 6. | 1. | 16. | 4. | 3. | | 1. | 6. | 1. | 17. | 6. | 3.07 | | 1. | 6. | 2. | 15. | 8. | 3.07 | | 1. | 6. | 2. | 16. | 10. | 3.05 | | 1. | 6. | 2. | 17. | 14. | 3.06 | | 1. | 6. | 3. | 15. | 16. | 3.06 | | 1. | 6. | 3. | 16. | 18. | 3.09 | | 1. | 6. | 3. | 17. | 20. | 3.04 | | 1. | 10. | 1. | 28. | 4. | 3.12 | | 1. | 10. | 1. | 29. | 6. |INCOMMUNICADO |  Misha observation | 1. | 10. | 2. | 27. | 8. | 3.13 | | 1. | 10. | 2. | 28. | 10. | 3.13 | | 1. | 10. | 2. | 29. | 14. | 3.12 | | 1. | 12. | 3. | 33. | 16. | 3.13 | | 1. | 12. | 3. | 35. | 20. | 3.13 | | 2. | 1. | 2. | 5. | 14. | 3.13 | | 2. | 3. | 2. | 17. | 14. | 3.09 | | 2. | 4. | 2. | 23. | 14. | 3.12 | | 3. | 5. | 1. | 15. | 4. | 3.11 | | 3. | 6. | 2. | 35. | 14. | 3.13 | +--------------+--------------+--------------+--------------+--------------+--------------+ 28 July 2010G. Rakness (UCLA) 6 N.B. Cannot readout the ADC values from two TMB’s on ME–…  Likely because their 3.3V-line voltage is too low… (… all TMB’s Misha observed in his elog are on this list…)

7. Comparing 904 Values with P5 Values The voltage drop on the 3.3V-line from CRB to TMB ADC was measured using a Digital Voltmeter on 5 TMB’s at 904 At 904: Average voltage output by CRB = 3.31V –At point 5, average voltage seen by DCS = (3.346 ± 0.015)V (R. Clare [UCR])  Given that the 3.3V-line specification is (3.3V±5%), and that voltage drops can only reduce this voltage, it makes sense to increase the output voltage at the CRB… At 904: Average voltage drop from CRB to TMB ADC = 0.12V –The (delivery voltage + drop) measured with a DVM at 904 is consistent with the voltages measured with TMB ADC at p5 (page 4) –In addition, this voltage drop is consistent with measurements on the reference TMB at UCLA 28 July 2010G. Rakness (UCLA)7

8. Tracing the Voltage Drop from CRB to TMB ADC on 3.3V-line At 904: from CRB to TMB ADC, the biggest voltage drops occur at two places... Through the backplane = 0.03V Through the socket fuse F2 on TMB = 0.07V –It was found that replacing fuse with a higher amp fuse could reduce the voltage drop from ~0.07V to ~0.04V… 28 July 2010G. Rakness (UCLA)8

9. Proposed Plan of Action for the August Technical Stop (I) 1.Increase the voltage coming out of the 3.3V-line on the CRB from 3.35V to 3.45V. In order of priority… –VME–1/6 (9 TMB’s) –VME+1/10 (8 TMB’s) –VME–1/10 (5 TMB’s) –VME+1/5 (4 TMB’s) –VME–1/12 (2 TMB’s) –VME+4/2 (2 TMB’s) –VME+2/3 (2 TMB’s) Longer term… increase voltage from all CRB’s 28 July 2010G. Rakness (UCLA)9 Note: accessing and making modifications to CRB’s at UXC, no matter how cleverly it is done, is going to be extremely challenging…

10. Proposed Plan of Action for the August Technical Stop (II) 2.On single TMB’s below spec, replace the fuse in the sockets with a higher amp fuse Longer term… replace the socket fuse with a different type? (TBD) 28 July 2010G. Rakness (UCLA)10

11. Monitoring TMB Voltages DCS plan to readout TMB voltages and temperatures TMB voltages, currents, and temperatures read out by XMAS for EMUlib v9.11 X2P and PVSS receive values for EMUlib v9.12 28 July 2010G. Rakness (UCLA)11 R. Clare (UCR), J. Liu (FNAL), and E. Juska (FNAL)