Re: Tektronix 545 Oscilloscope fault
I think we are misunderstanding each other...
The -150V supply _is_ critical, and it does affect the calibration of the entire 'scope. But if the 'scope has been calibrated with the -150V supply at slightly the wrong voltage then setting it spot-on with a well calibrated meter could actually make things worse.
If the -150V supply is right then the others should be too.
In any case, a slight error in any of the supply voltages (no, not a supply entirely missing due to a component failure) will not cause the problems the original poster has.
So I suggest checking the supply voltages as the first thing to do. No piece of electronics will work without a power supply. If one is missing or very incorrect in voltage then find out why. But do not at this stage adjust the -150V trimpot in the hope that it will get the thing working. It won't. And remember that +/-1V in 150V is an accuracy of better than 1%, and a lot of cheap DMMs will not manage that.
|