I managed to pickup a used BK Precision 1474 oscilloscope for $10 and figured it would be a good gamble for the price, I powered it up and the CRT had no spot. I did some hunting and managed to find the original service manual as a pdf, and started working down the troubleshooting chart. I have made it as far as a section that wants me to check the voltage across a "radiator plate". So far I have found absolutely nothing that mentions what this part is, and google just wants to show me car radiators for sale. I am 16, and this is my first scope, so any help figuring out what this is would be deeply appreciated.
Schematics are here (Diagrams and schematics start on PDF page 25.)
Here is a screenshot of the chart that wants me to check the radiator plate:
Thanks in advance!
EDIT:
Thanks for digging into this with me guys! 🙂
The general consensus seams to be that it is some kind of thermal plate on a transistor or something. So I will probe around when I get home, and will update when I do!
I also added a link to schematics for those of you that know more then me to have a look at.
Best Answer
I think they're referring to the deflection plate connections — pins 8 and 10 on the CRT, which connect to R474/L407 and R475/L408, respectively, on the vertical output amp board X73-1220-00. This is supported by the fact that if they are "NG" (no good), then the chart concludes that the vertical amplifier is defective.
Similarly, the next step has you checking pins 10 and 11 on a different board (it says X74-1210-00, but I think they really mean X74-1080-00). These would be the horizontal deflection plates (pins 12 and 13 on the CRT), because if they are NG, they have you focusing on the horizontal amplifier.