Hi All,
This board (see pictures) comes from the late 60's oscilloscope I am trying to repair.
I am confused when it comes to some components. I suspect they are capacitors (the silkscreen would suggest pF) but the marking on them is a bit confusing - 20M for 20p silkscreen, 10M for 10p, 510K for 500p, 2000K for 2000p...
I removed one "51K" (marked 50p on the board) and tested it. Capacitance jumps up and down crazily at the beginning and then it settles at steady "47pF". The resistance test shows "OL". This would suggest capacitors as marked on the board's silkscreen but I just wanted to make sure. Especially, that the symbol used on the silkscreen is very similar to the resistor (an empty rectange but a bit shorter than the resistor's).
Also, can I replace them with standard ceramic caps? They are all marked with "WV. 250", so should I assume "Working Voltage" 0.25V or 250V? I think 250V would be safer.