TB7100 Service Manual Power Supply Fault Finding 135
© Tait Electronics Limited October 2005
4. For the internal-options power-sense option the link LK4 should be
inserted (see Figure 9.2). Connect +3.3V DC (more than 2.6V to
be precise) from the power supply to the
IOP GPIO7 line (pin 15 of the
internal-options connector SK102). Check that the power-up signal
at pin 5 of IC602 (see Figure 9.1) is high.
Remove the +3.3V supply and ground the
IOP GPIO7 line (to be
precise the voltage on the line should be less than 0.6V). If the power-
up signal is now low, conclude with Step 5. If it is not, check for
continuity and shorts to ground between D604 (see Figure 9.1) and
pin 15 of the internal-options connector SK102. Repair any fault and
go to Step 5.
5. After checking all the relevant power-up options, and if necessary
repairing any faults, go to “Final Tasks” on page 123. If the fault
could not be found or repairs failed, replace the main-board assembly
and go to “Final Tasks” on page 123.
To Next Page
Loading...
