This manual may contain references to HP or Hewlett-Packard. Please note that Hewlett-. Packard’s former test and measurement, semiconductor products and. Chapter 2 Getting Acquainted with the HP C How to Get the Most Out of the HP C “General Information” section of the Operating Manual has. This page is devoted to the repair of my HPC Network Analyzer. section or page of the HPC Service Manual PDF file) and got these results.
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But with some determination and efforts even a very complex equipment can be repaired. With two independent display channels available, you can simultaneously measure and view the reflection and transmission characteristics of the device under test in overlay or split-screen format on the crisp color display. After spending time with a pen, paper and a continuity meter to understand the schematics, and search on the Internet for the datasheets of the parts used in the pre-regulator, I got what I wanted which was understanding the power supply PWM controller circuit.
Checked the pin 2 again, the voltage was changing erratically. The Service Manual instructs to remove the boards one by one to identify which one may be causing the overload condition, which I did with no success. It then became apparent that the problem may be with the PWM controller which for some reason restarted intermittently.
It can be seen in the above picture along the edge of the right half of the box. I had no choice other than to download the Service Manual and deal with the problem.
Manuals – KO4BB
And the results were, as you can imagine, bad at least for the first one; the manuxl ones seem to be similar to what the manual says, but with some offsets. The left half of the box had the power stage and rectifiers.
More to come soon Here you have a test pattern displayed on the Sony monitor subassembly yes, it is a Sony Trinitron tube! The Hewlett-Packard C Vector Network Analyzer is a massive literally instrument for measuring complex reflection and transmission parameters of the device under test DUT circuits.
I cut one of the legs manial and connected the ohmmeter across the capacitor – it measured a resistance. Then all of a sudden the VNA began cycling the power again even with the display power disconnected.
EB5AGV’s Workbench: HP-8753C repair
Setting Observed frequency Error approx kHz I got a gut feeling that the problem may be with the power supply itself. In order manuao get the proper colors displayed, I got the display module out and looked for the R-G-B gain pots. I did also some CW tests and, as a sample, a 1. As you can see, I was right manal the offset being an anomaly. Also, it was unusual that this type of component, a small axial bypass capacitor, would develop resistance and caused that much of a problem, rendering the whole system unusable.
You can see from page of the PDF what the different displays should be in a working unit. The two halves of the box have connections with each other via disconnectable wire cables. Basically, the unit was mechanically sound, except for the missing display buttons cover an spare is already on its way: Source adjustments As I said before, I was afraid of trying any test which would write on the configuration EEPROM, as I had no way to restore the previous configuration if things got worse Unit as received I got the unit knowing it had several faults, so there was not surprise when I got the first display from it: If the overload condition was still present it caused the device to continuously cycle the power.
Here you have the previous apparently good check of the YO coil drive, which showed some offset: So I went bed manuzl about 3AM local time This time removing one or two boards in no particular order allowed the power supply to start. The bad C6 bypass capacitor was replaced with a new mica red one which can be seen in the center of the picture. So I run all the tests which were related to it.
But I stopped early, as it suggested to do a recalibration and I mxnual afraid that would only make things worse; I checked the RF OUT in CW mode with an spectrum analyzer and an oscilloscope, at different frequencies. Thanks to the used equipment market for producing such a nice opportunity to learn.
EB5AGV’s Workbench: HPC repair
That puzzled me off completely. The easy-to-use softkey selection of measurement functions allows you to measure the magnitude, phase, or group delay characteristics of your device under test.
But before doing them, I thought that a good way to know if the rest of the system was OK, was to check the unit with an external reference. The manuwl part of the schematic shows the critical elements of the PWM controller. Good example of something being at the wrong place at the wrong time!