Key-Down Powerup - HP 54520 Series Service Manual

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why
To troubleshoot the instrument
Default Setup
A Default Setup is provided to assure the instrument setup is in a known default
state. The default setup prevents previous setups from interfering with the next test.
It also simplifies the instrument set up procedure. Use the default setup when a
procedure requires it.
To set the instrument to the default state:
In the CONTROL section of the instrument, press Recall .
Key-Down Powerup
The key-down powerup is a more forceful reset than the default setup. It is usually
used before self cal or when troubleshooting. It is also the first step toward loading
new software through the disk drive.
Hold any front panel key depressed.
Cycle the power while the key is depressed.
When the display becoms visible, release the key, then press any key except
the (blue) key.
The first message during the key-down powerup asks if you want to update system
code. If you want to continue with a normal key-down powerup you press any key
other than the shift (blue) key.
To troubleshoot the instrument
The troubleshooting is used to isolate problems to a faulty assembly. When the faulty
assembly has been located, use the disassembly/assembly procedures in chapter 6 to help
direct replacement of the assembly.
The trouble isolation flowcharts are the troubleshooting guide. Start with the flowcharts when
repairing a defective instrument.
The flowcharts refer to other tests, tables, and procedures to help isolate trouble. The circled
numbers on charts indicate the next chart to use for isolating a problem.
The flowcharts start on the following page.
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