1. LFC Troubleshooting Report G. Rahmer 2008-12-02

2. 2 The problem CCD#2 reported as failing intermittently in August '08 Bad images become more common in October. CCD#5 is also reported as having problems, although not as severe. Camera is brought to campus in November 4th. LFC Focal Plane

3. 3 Bad clock signal found Parallel clock P1A (CLK#4-p1 ->P0-p59) (low level floating) Normal parallel clock (not acquired at the same time)

4. 4 Actions Replaced faulty clock board (SN269) by spare board from lab stock (SN336). Replacement board required an adjust in the gain of volt ref op-amp to match original LFC board: changed R70 from 10 Kohm to 4.99 Kohm. Will send faulty board for repair to Leach (if possible).

5. 5 CCD#2 Before and After (warm) Bias - November 20 (ccd.001.2.fits) Bias - November 28 (ccd.001.2.fits)

6. 6 CCD#2 Before and After (cold) Bias - October 26 (ccd.109.2.fits) Bias - November 28 (ccd.027.2.fits)

7. 7 New issue: regularly-spaced spikes in CCD#2 and CCD#5 (not seen in others) CCD#5 CCD#2 Spikes spaced at app. 60 lines (2x2 binning) Time-invariant (same positions for different images)

8. 8 Spikes in 1x1 binning are spaced at 30 lines CCD#5 CCD#2 Spikes spaced at app. 30 lines !! Expected 120 lines (as it is 60 pixels for 2x2 binning)

9. 9 LFC cold, 0s, 2x2 (before, on Palomar) /scr1/20081026/ccd.063.n CCD5 CCD2CCD1 CCD3CCD0 CCD4

10. 10 LFC cold, 0s, 2x2 (after, in Lab) /scr1/20081026/ccd.063.n CCD5 CCD2CCD1 CCD3CCD0 CCD4

11. 11 LFC cold, 300s, 1x1 (Lab) /scr1/20081201/ccd.012.n CCD5 CCD2CCD1 CCD3CCD0 CCD4

12. 12 LFC cold, CCD3 (Lab) amplifier glow /scr1/20081201/ccd.005-7-9-12.3 300s, 2x20s, 2x20s, 1x1300s, 1x1

13. 13 CCD3, 0s, 2x2 (before and after) /scr1/20081026/ccd.063.3 /scr1/20081201/ccd.007.3 October 26 (Palomar)December 01 (Campus Lab)

14. 14 CCD3, 300s, 2x2 (before and after) /scr1/20081026/ccd.079.3 /scr1/20081201/ccd.005.3 October 26 (Palomar)December 01 (Campus Lab)

15. 15 CCD3 (Palomar, October 26) /scr1/20081026/ccd.079.3

16. 16 LFC cold, CCD3 (Lab, amplifier glow) /scr1/20081201/ccd.005.3