Approximately 250 DBs were sent to Penn from Queen's for debugging. The goal is to determine if we can categorize boards with problems without extensive measurement time so that we can quickly determine which chip (if any) needs replacement.
We plan to use the level 3 testing code here at Penn to help determine if fixed boards were in fact fixed. Queens will also need to test these boards.

Notes:

1. Queens tests are absolutely critical to continued progress. If it turns out that (say) we are damaging CMOS chips during our debugging process we will want to know that as soon as possible.
2. Double counts are boards for which a chip replacement did not work so another chip was replaced.
3. There is a reasonable chance that the 20 failed boards are mainly symptomatic of test stand and test stand user teething pains, and that these boards will be reparable.
4. The "component" problem class included one missing resistor which, when replaced, fixed the board, and one replaced capacitor, whose replacement did not fix the board. About 20 boards are expected to have problems of this nature, in particular those for which resistor replacement fixes the failure of the board to balance.
5. About 10 boards have trigger problems which should be fixable, but they will be looked at later.
6. The SNOD problem class above was comprised of about 20 boards which were preselected for low impedance on the integrator. Thus the SNOD sample was enriched in this type of problem. It is unknown at present how this will affect future SNOD repair yields.
7. The amount of time it takes to diagnose a DB is ROUGHLY 15 minutes, and 10 minutes to replace a chip (done by a separate person). It then takes about 5 minutes to recheck the DB to see if the replacement has worked. In about 1/4 of the cases, this cycle has to be repeated when another chip on the same DB is replaced.
   The total time per board thus comes to about 20-25 minutes.
   We are currently spending a total of about 40 person-hours/week on this activity, so unless these numbers are way off, we would be done in about 3 weeks if not for the fact that we are going to lose about half of the total labor during finals, which start in about 2 weeks, and over Christmas break.