I've got a TEK 2430 that seems to work just fine for about 15 mins. Sometimes more. All tests PASS.
I've input a function generator and all different inputs look fine on both channels. Then after 15 mins and sometimes more, I'll look over at it and the screen is still showing a nice looking sine wave, for instance that I've input, but when I go to make a change, the scope is frozen with that image and no other controls seem to make a change.
Relays click when I make some control changes but the screen remains frozen with that sine wave image.
When I turn the scope off and wait 20-30 secs and then turn it back on, it will show the standard horizontal line but will not detect an input.
I can turn the scope completely off and after a few hours it will again come up and work just fine but eventually the same thing happens.
Scopes are not my expertise so if anyone has an idea where to start looking, I'd sure appreciate some guidance.
Thank you. John / K7RLD