Chuck, with known good CTT board exchanged for the one in the failed scope, all cables properly reattached.
A5 board is know good and had no SMD leaky caps.
Only, partial success, CTT works but the following faults on self test:
Test 01 -06 PASS
CT TEST 81 Fail 03
CT Test 86 Fail 02
All others PASS
So really confusing results.