Hi again,
Here is an update about the restoration of my Tek 465. Now that the screen is working, I started to progressively reassemble and test everything. Unfortunately it has many other problems. "It's one sick puppy" as Dave would say
But those problems are a lot easier to troubleshoot.
First I had to re-attach the small chop mode transformer and several other components that have been ripped by someone who carelessly opened the case. I used rigid copper wires to reach as close as possible to the windings. Then I made a small plastic cover so that is wouldn't break again.
After that, I removed the two horizontal boards in order to access the VAR shaft coupler which snapped and replace it with the same coupler that I borrowed from the astigmatism pot. I also cleaned all leaf switches with IPA and paper. I got so fed up with having to desolder 20 wires each time I want to remove those boards that I decided to install connectors. A lot of other connections use the same standard connectors, I don't know why Tek didn't do it the first place, those wires don't carry any high-frequency signals. Now I can get the vertical board whenever I want by just soldering the trigger BNCs
Then I reinstalled the timing boards and the timebase selector which was a huge pain to properly align. I never used an old Tek before and this selector wasn't properly attached when I got this scope but now that it works I must say that this is the coolest mechanical switch ever. The thing is a masterpiece of mechanics with all the mechanisms to handle the two timebases and the feel and the sound of it operating is totally pornographic.
With the scope in one piece I started to see traces, but they were all jumpy and noisy. Things where getting especially bad whenever I moved or touched the device. The problem concerned both channels even in GND position. The issue was somewhere close to the CRT, so I started lightly bumping various parts of the scope until I found where it was especially sensitive. It was on the scary circuitboard that connects to the delay line and the vertical deflection plates. Fortunately my unit has the integrated circuit version unlike ModemHead's where 100 components are just soldered together in free air. I took it out and it really looked like someone with poor soldering skills took a go at it, the output wires were almost broken, so I replaced them. Then I looked for cold joints and there were maybe one on one of the silicone resistors. Also the delay line connector was in an ugly condition and its shield legs were broken not making contact with the PCB. I did my best to straighten it and solder rigid wires in place of the broken ground legs. I don't know which of these repairs did the trick, but after them the traces became very stable.
After the multiplier replacement I hadn't adjusted the HV power supply and the CRT bias so the traces were kind of thick. Not having any DMM that goes beyond 1 kV, I had to improvise an HV probe. Luckily I found a high voltage 100 Meg resistor on an old printer PCB. I used it to make a 1000x probe. It did the job and I could adjust the -2450V rail which was way off. I followed the manual to set up the CRT bias and the traces became nicer.
Remaining problems:The 1X/10X probe lights don't work, probably the bulbs are burnt. I hesitate to replace them with LEDs.
There's something wrong with the intensity control. The knob is very hard to turn and it's very jumpy when I operate it. Also the calibration procedure often says to set the intensity on +15V with respect to a dedicated test point. On my unit this voltage only goes down to 23 Volts.
The B timebase is not sweeping. The A intensified mode works, I can highlight a portion of an input signal, but when I switch to either "MIX" or "B (DELAYED)" there's nothing on screen.
Calibration seems off here and there, I'll have to follow the complete adjustment procedure.
Various knobs cracked as described in my previous post, but thanks to Kibi and his scraped 475 I may be able to give the scope back its perfect visual aspect.