First Post! Not seeing much by the way of editing tools for posts so I'll do my best.
Test equipment:
Hantek DSO2C15 oscilloscope
Tektronix 2465A oscilloscope
Fluke 87 V multimeter
DE-5000 LCR meter
Siglent Technologies SDG1032X - set to arrive later this week
Operator Level:
BSEET "engineer" trained in soldering and de soldering correctly. Familiar with schematics, P&IDs, pinning charts, flow diagrams, etc.
Have restored several pieces of vintage equipment (Tube amps, tube test equipment, Epson HX-20 laptops,etc)
Device Under Test:
Tektronix 465B #107437 with option 5 (TV Sync Separator). Boards have date of 1978
Last Calibrated:
6-30-1994
Last Used:
~20 years ago
Synopsis:
X-Y mode mostly works with extra signal anomalies present (rolling of signal on screen), Channel modes have some odd interactions with time base and cause lockup. Can sometimes get a signal to display properly.
+5VDC rail is low at 4.11V. All other supplies are within spec to the service manual including the high voltage.
So far:
Applied DeOxit D100L to push button switches only
Checked vertical attenuators with no signs of corrosion. Leaf switches look clean and functional, I didn't touch them as they appear very fragile
Gave all switches, knobs, buttons, levers a good workout.
Oscilloscope appears to be in good physical shape. Circuit boards appear to be visually OK, no signs of damage or leakage
Replaced all tantalum capacitors with aluminum electrolytic
Troubleshooting via ther service manual indicates possible faults in the Vertical Pre-Amp and A+B Sweep generator. I've tried getting a trace to appear but I've found many times the scope appears to "lock up". The trigger LED will light up and then basically everything stops functioning and I have to turn the scope off and back on.
Vertical Pre-Amp
+4.14V connected
+4.36 disconnected
Once I get the signal generator I'll start tracing the signal through the channel A vertical amp. In the meantime I pulled each transistor on the vertical pre-amp board and checked them for "go/no-go" with a arduino based component tester. They all tested "go", I did not pull the datasheets and compare the specs.
I did all the testing with the tantalum installed and then with the electrolytic. Replacing the capacitors did not fix the issue or introduce any new issues.
Are there any common failures that I should be checking for before going into the in-depth signal trace?
I've put some pictures up on my Google photos. These images show some of the anomalies when applying a sine wave and square wave using a cheap signal generator. The anomaly is not from the signal generator (verified with other scopes)
