Hello,
First time poster here. Hope someone can offer some basic help for a new oscilloscope user. Picked this scope up dirt cheap at a local flea market. Which makes sense, as it is covered in a large amount of dust and dirt. I think it came out of a barn.
Right out of the box? It blows the RIFA capacitor to about 19 chunks of stink. I've got a different replacement of the same value(s), but it's a polyester capacitor. Seems the factory ones are known for going up and out in a blaze of glory.
Anyhow, I start playing with it again, and note it's dead with that cap out of circuit. (schematic shows it should still fire up with it out of circuit) I traced it back to a blown out thermal fuse on the transformer. Have a fast blow fuse rigged into it for the moment--and I can not locate any sign of a replacement thermal fuse for that transformer at all. Google left me high and dry on that one.
Fast forward to the reason I stopped in. Channel 'b' seems to have full function. Position goes up/down and all that good stuff, and if I change the time on the knob--I get a bit of static on the screen which seems to be normal.
Channel 'a'? Position does not have any effect on the trace. Turning the function knob while it should make a bit of static? Totally nothing. Just a line at dead 'zero' (center).
While I used to be pretty trained in electronics, I'm about as brain dead as it gets with oscilloscopes. I'm fair with a soldering station and multi meter--and actually repair flat panel TV's on the side--but that's more of a research what usually fails..and replace parts. I'm trying to get back into the diagnostic work again.
I have the test leads coming in next week, and I'm confident channel 'b' should be okay. So I'll at least be able to use that channel for the intended purpose. But I would like to get channel 'a' functional. Has anyone had experience working on this type of issue? I can of course supply photos of any parts and info as requested. There is a service manual online as well that I've already downloaded. It's pretty much Greek to me trying to understand it. (25 years ago when I did electronics back in school? No problem. That part of my brain is covered in more dust then this oscilloscope.)
Many Thanks!! I'm pulling double duty at work so my response time might not be the greatest.
S-