6-8HP 8517B S-Parameter Test Set ManualHP 8517B Test Set Replacement ProceduresAssembly Replacement ProceduresFan AssemblyReplacementB1 Fan AssemblyTurn off the test set and disconnect the power cord from the ac-power mains.WARNING Electrocution can result if ac power remains connected to the test set duringthis procedure. Disconnect the ac power cord before starting.To replace the B1 fan assembly, remove T1 transformer to expose the ends ofthe fan wires which must be de-soldered from the line module, FL1. Refer toChapter 7, “Replaceable Parts” in this manual for a detailed view of the fanand transformer hardware.1. See Figure 6-2 for component locations.2. Position the test set on its right-hand side.3. Using a 5/16-inch open-end wrench, remove the hard-line cablesconnected between the couplers A7 and A9 and the bulkhead connectorsJ2 and J5.4. Unplug the transformer connector at J2 on the A15 regulator board.5. Using a large Pozidriv screwdriver, remove the four screws and washersthat hold the transformer onto the rear panel.6. Using a large Pozidriv screwdriver, remove the screw that holds thetransformer angle bracket to the main deck.NOTE The transformer wires soldered to the line module are short, so do not pullthe transformer out too far.7. Carefully remove the transformer from the test set and place it on thebench near the test set.8. Strip the heat shrink tubing off the two fan wires, then de-solder thewires from the line module. Cut any cable ties restraining the fan wires.9. Using a small Pozidriv screwdriver, remove the screw and lockwasherthat secure the green/yellow fan ground wire to the top of the rear panelframe.10. Using a small Pozidriv screwdriver, remove the four screws that hold thefan to the rear panel. Remove the fan assembly.Power TransformerReplacementT1 Power TransformerTurn off the test set and disconnect the power cord from the mains.
