HP 70908A, Руководство по обслуживанию

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If Y our HP 70908A RF Section is P owered On But Not
Responding Correctly
If the HP 70908A RF section does not complete its power-up sequence , or if it causes the bus to
hang up , the following procedure may be used to help troubleshoot the problem.
T o solve this problem:
Set the mainframe line switch to OFF . Remove the RF section from the mainframe , and then
remove the left-hand side cover from the module to gain access to the A12 controller .
Install the module service extender (HP part number 70001-60013) and connect the RF
section to the extender cable .
Set the mainframe line switch to ON.
Measure the +5 V supply at A12U17 pin 3.
If +5 V is present, there is a problem with the A12 controller .
If +5 V is not present, remove the ribbon cable to the A14 front panel board .
Remeasure the voltage at A12U17 pin 3.
If +5 V is present, the A14 front panel board is loading down the +5 V .
If +5 V is not present, check A12U17 pin 1 for +8 V (unregulated).
If the voltage on the A12U17 pin 1 measures +8 V , there is a problem on the A12 controller.
If pin 1 does not measure +8 V , refer to \Troubleshooting the A10 P ower Supply/Driver " in
Chapter 4.
If necessary , obtain service from Hewlett-P ackard. (Refer to \If Y ou W ant Hewlett-P ackard to
Service Y our RF Section " in Chapter 1.)
3-4 Before Extensive Servicing