Inspect The Motherboard - Agilent Technologies 8719ET Service Manual

Power Supply Troubleshooting
If the Green LEDs of the Post Regulator (A8) Are Not All ON
5. Of those assemblies that are left on the list, remove or disconnect them from the
analyzer one at a time.
them, sorting them from most to least accessible.
assemblies that are supplied by the assembly that is being removed. After each
assembly is removed or disconnected, switch on the analyzer and observe the LEDs.
• If all the LEDs light, the assembly removed (or one receiving power from it) is faulty.
• If the LEDs are still not on steadily, continue with the next section
Motherboard."
Table 5-4 Recommended Order for Removal/Disconnection for Troubleshooting
the A8 Board
Assembly to Remove
1. CPU Board (A7)
2. R Sampler (A4)
3. A Sampler (A5)
4. B Sampler (A6)
5. Source Control (A9)
6. Front Panel Interface (A2)
7. Test Set Interface (A51)

Inspect the Motherboard

Inspect the motherboard (A17) for solder bridges and shorted traces. In particular, inspect
the traces that carry the supplies whose LEDs faulted when A8TP4 (SDIS) was grounded
earlier.
5-16
Table 5-4 on page 5-16
Removal or Disconnection
Method
Disconnect W87
Unplug from A17 and
Remove
Unplug from A17 and
Remove
Unplug from A17 and
Remove
Disconnect W91
Disconnect W84
Disconnect W89
shows the best order in which to remove
Table 5-4 also lists any associated
Other Assemblies That
Receive Power from the
Removed Assembly
None
None
None
None
None
Front Panel Keyboard (A1)
Transfer Switch (S4)
LED Front Panel (A56)
8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
"Inspect the
Service Guide