I've checked out the z-system and everything looks OK from here.
Below is the output from MULTI-Z (aka ZTEST)... all the z-cards
and LTCs are OK and the FAIL in crate 18 is normal because the
RBOX timing is set up for the FLT cards and not z-cards.

Cheers, John

+-----+----+----+-----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
|Crate|LTC |    |     |                                      SLOT NUMBER                                             |
|Num  |Ser.|    |     +----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
|     |Num.|FAIL|loops|  2 |  3 |  4 |  5 |  6 |  7 |  8 |  9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
+-----+----+----+-----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
| 1   |#60 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
| 2   |#61 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
| 3   |#62 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
| 4   |#63 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
| 5   |#64 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
| 6   |#65 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
| 7   |#66 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
| 8   |#67 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
| 9   |#68 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
|10   |#69 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
|11   |#70 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
|12   |#71 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
|13   |#72 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
|14   |#73 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
|15   |#74 |    | 100 |n   |    |n   |n   |    |n   |    |n   |n   |    |n   |n   |n   |    |n   |    |n   |    |    |
|16   |#75 |    | 100 |n   |    |n   |    |n   |    |n   |n   |    |n   |n   |    |n   |n   |    |n   |    |    |n   |
|17   |#51 |    | 100 |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |    |
|18   |#52 |FAIL| 100 |    |    |    |    |    |    |    |    |    |n999|    |    |    |    |    |    |    |    |    |
+-----+----+----+-----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+
Jumpback register = 345   Pipeline register = 439   Copy length =  50   Number of transfers =   1   Buffer cycling ON