1) First determine which module is causing problems. With the hardware configured for PBG7
operation you can change the software configuration to PBG5 in the system status page, then
run the pulser. No power will be applied to stacks in the PBG7 module. Stable triggering now
indicates the PBG7 module is at fault.
If maloperation continues, next change the software configuration to PBG1. No power will be
applied to stacks in the PBG5 module (or PBG7 module). Stable triggering now indicates the
PBG5 module is at fault.
If maloperation continues the PBG1 trigger module is at fault. This being so the system cannot
be operated, contact Kentech for advice.
2) If the problem lies within the PBG7 module, you can isolate the fault using a matrix
procedure using test mode 7 under the test menu.
In this mode you can disable each one of eight pulse cards in turn and run the pulser, you
should find with one particular card disabled the problem goes away. Leave this card selected.
Next you can disable each one of eight rows of stacks in turn and run pulser, again you should
find that with one particular row selected the problem disappears. Leave this row selected.
Now with the correct card and correct row selected, the number displayed in brackets on the
first line is the global number of the only stack that is common between the card number and
the row number, ie the faulty stack. You should disable this stack in the stack status pages and
recheck that the pulser runs normally.
Disabling any one stack in the PBG7 module reduces the output by approximately 1/60 part,
the unit may be operated with several stacks disabled before repair is required to meet
specification.
3) Similarly if the problem lies within the PBG5 module, you can try to isolate the fault using
test mode 5. Test mode 5 does not work on card number 0 in the PBG5 module which
contains the four trigger stacks numbers 2 to 5 inclusive (local stack numbers 0 to 3), see
architecture diagram. If test mode 5 does isolate the fault, then the fault lies in one of the output
stacks 6 to 21 inclusive (local stack numbers 4 to 19) and it is permissible to operate in PBG5
and PBG7 configuration with the stack disabled though there may be some increase in risetime.
