Fixing my OS-8100 Goldstar Oscilloscope

It's been a while since my  last and lonely post.  I am not a writer, that's a fact. But I'd like to document some stuff,  with the hope that  might help somebody or myself someday.
Yesterday I was able to fix my 100Mhz Oscilloscope. It has been out of duty for 7 years already and it was about time I did something for it.
The unit turns on and it shows only one dot on the screen. The vertical position knob worked properly and there was no horizontal control at all.
Initially I thought it was a problem in the horizontal module. Not having schematics for the model, I replaced all electrolytic capacitors for brand new ones.  The horizontal amplifier module share the board with the power supply module, so I also changed the power supply capacitors. No luck.
Fortunately there is silk screen indication of the power supply outputs. The 130v output was providing 30 volts instead.
I checked all diodes and transistors, they were OK.  There are two TL72CP op-amps in the power supply circuit. I did not have replacements but I measured the voltage difference between the input pins and it was 0. So, I supposed that the Op-amps where fine.
With no where to go, I decided to measure all resistors and to my surprise I found one broken 130K resistor. Just at that moment, I stumbled upon the schematics on the Internet. After 7 years of looking unsuccessfully for it, it was a happy moment.
The resistor was part of of adder circuit used to compare the 130v output with a 55volts reference that comes from another part of the circuit.
After replacing the resistor,  I got the 130v on the output and the horizontal trace on the screen.  I was so happy that I forgot to place the protective plastic sheet that cover the back of the board and protects it from touching the top of the chassis. The power supply got broken again, but,  fortunately, it was the same 130v power supply module was the culprit one more time.
This time, it blew up the PNP 200v transistor that is used as regulator of the power supply, a 2SB861 transistor. I found it on eBay and received just yesterday. I replaced the broken one, and now very carefully I closed the oscilloscope making sure I was not missing anything.
Bingo! My scope is back in business.

While waiting for the transistor to arrive from Asia,  I downloaded LT SPICE and simulated the 130v power supply. It works perfectly. The op-amp compares the output versus a 55v reference and drives the PNP transistor where the voltage is in series with the unregulated output of the filter capacitor. The voltages and current of the simulation were exactly as the ones I measured after fixing the board. Nice.