Hi,
I purchased an HP 1740A scope on ebay a few weeks ago. This is my first time repairing a scope and I have a question(s).
When I first got the item, I noticed the mains setting was not set for US mains. After switched it to US mains, the unit powered on. I took the covers off and probed the power supply board and all the voltages are correct. At this point, I injected a 1khz sine wave to channel A. No signal appeared, so I adjusted the intensity knob, but no luck. I pushed the Beam Find button and then I saw my signal.
This is pretty much where I'm at at the moment. When I get home from work in a couple of hours, I will read through the service/operating manual to see if I can't find any hints in there, but until then, I thought I would post here.
Any feedback would be appreciated...As far as I know, I have the scope configured correctly to display a signal and when I move the volts/div or the times/div, I do see the signal change. It's It's not changing as you would expect it to though. Meaning when you adjust the volts/div with the Beam Find button pressed, the signal looks different from when the Beam Find button is released. I just checked this with an old analog scope at work to confirm this. But again, I can only view the signal when I push the Beam Find button.
Would love to get this little beast back up and running again.
I purchased an HP 1740A scope on ebay a few weeks ago. This is my first time repairing a scope and I have a question(s).
When I first got the item, I noticed the mains setting was not set for US mains. After switched it to US mains, the unit powered on. I took the covers off and probed the power supply board and all the voltages are correct. At this point, I injected a 1khz sine wave to channel A. No signal appeared, so I adjusted the intensity knob, but no luck. I pushed the Beam Find button and then I saw my signal.
This is pretty much where I'm at at the moment. When I get home from work in a couple of hours, I will read through the service/operating manual to see if I can't find any hints in there, but until then, I thought I would post here.
Any feedback would be appreciated...As far as I know, I have the scope configured correctly to display a signal and when I move the volts/div or the times/div, I do see the signal change. It's It's not changing as you would expect it to though. Meaning when you adjust the volts/div with the Beam Find button pressed, the signal looks different from when the Beam Find button is released. I just checked this with an old analog scope at work to confirm this. But again, I can only view the signal when I push the Beam Find button.
Would love to get this little beast back up and running again.