From PREX Wiki
September 10th, 2018 Testers: Cameron
Replace battery in LHRS ROC 25 (hallavme14) so that NVRAM doesn't get erased after each power cycle.
- The battery (small yellow rectangle with 4 pins) used as a replacement is labelled "990ST M4T28-BR12SH1 TIMEKEEPER SNAPHAT MYS 99 611" and Cameron has 4 more copies with the same label, plus the old one that was probably bad.
- Replacing the battery is easy, you just pull out the ROC and the battery is installed over a integrated chip next to the serial port on the bottom left and it just snaps into place.
- I did not do a power cycle test in the hall, but I did restore the RAM remotely (from apar@adaq3:~/doc/vmeram.doc)
- While moving the modules around the TI to Happex Timing Board twisted pair cable came undone and I did not put it back.
- This means that for now the LHRS can only run in Trigger Supervisor mode (not standalone HapTB mode).
- Verify the RAM stays by doing a hardware power cycle
- Replicate battery replacement in all other ROCs to prevent this issue from reappearing (Cameron has the batteries)
- Replace the HAPTB DAC to TI module twisted pair connection
- Add HAPPEX Timing Board to Injector
- Test all ADCs in Injector
- Make a bank for all ADCs