Long time no updates .. but hey I am on the good track to restore the machine.
Replaced the big fat caps with new ones ... and I managed to get back to life the power supplies. i had to replace opamps and tantalum caps, a bridge .. but hey all power supplies are spot on smooth as a baby's bottom. Even more all front controls for teh scope look like they work perfectly fine, i can see trigger active etc. which is a pretty good sign.
I used the black wire GND connection - actually you have to bridge only in two places . So far the repair looks neat.
Now i have one question - if you look at the LV power supply schematic - CR1415 - is blown. I disconnected it after it took out the smoothing cap on the 15V rail supply out , after I fixed them (so i cooked again an electrolytic
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
). After diconnect I got the supply's going again ; of course with the required fixes etc. The service manual says
152-0107-00 SEMICOND DEVICE:SILlCON,400V,400MA G727<--(this is the manufacturer part number)
that is a Si rectifier diode with 400V reverse voltage and 400mA forward current found no eqiv for it. G727 is some old diode made by Texas Instruments from what I managed to dig out, and i did not find a data sheet.
Like I said, i am quite a newbie, but I read up and learn as i blow things up ... now can someone illuminate what is the role of that diode between the 50V unregulated and 15V unregulated rails ? Some kind of surge suppressor - discharge thing ? Everything works fine without it but I wonder what can be the long term effects of it missing. I guess i can replace it with something similar also.
Back to the restoration/fix status ; power rails are ok, all looks good on the front panel but one huge missing thing - CRT is literally not turning on. Confirmed that is the HV generator; that uses a HF generator ~50Khz and and fly-back transformer to generate the 2KV to drive the CRT. Sometimes when I turn the scope on I can hear some little crackling. Just more fun ahead .. i hope to get away without needing a HV probe