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This is the spot to get some help.
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After reading threads for a few years, my thoughts on how to help people help you: Get the service manual(Check, good start) Get a good picture of the scope, there are a "lot"!!! of knob position combinations that have to be considered. For example, It does not sound like it, but a check to be sure your not in horizontal external would be good. If there are not signs of mechanical damage, cycling the switches on a scope that has been sitting can help, flipping it in and out of horizontal external a few times to see if you have some switch dirt that will loosen up. A dirty Beam find button has a history of fooling people. Another thing is to give us an idea of what other tools you have to work with. Any scope history? Serial number? Some idea of your general location. Then it's to the power supply, do some reading first From an educational perspective "getting a crappy digital toy" depending on what it is, to look into the scope might have some merit. Take some time and don't be in a hurry John -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Benjamin A Sent: Monday, March 12, 2018 3:58 PM To: [email protected] Subject: [TekScopes] Another New Guy I'm very new at this, so please be gentle and use small words! I haven't done real electronics since college, but recently I've been bitten by the bug and wanted to relearn all the things I've forgotten both for myself, and for work (I teach programming and coach robotics!). Since I read that a good, old analog scope was preferable to a super cheap digital, I found a 475 on Craigslist. Bringing it home, I started learning how it worked and was starting to get really into it... When the horizontal sweep died. I was fiddling with the delay settings (super cool!) and the trace disappeared, instead lighting up something like the whole lower half erratically. I powered it off, and let it sit for a minute before powering it on, and it worked briefly before the sweep quit entirely leaving me with just a dot in the middle of the screen. I still get vertical movement when I connect the probe to the calibrator, and the dot can be moved with both the vertical and horizontal adjustment. There's also an issue with channel one-- the voltage display seems way too low. So I've read some of the service manual and some of the threads on here and people seem to imply that the low voltage power supply is the first thing to check, followed by the horizontal amp, but... My real question is: should I even be trying this right now? Should I stash this scope away, get a crappy digital toy to learn from and tackle this in the future? That would be a bummer, but I don't want to either make things worse or hurt myself (although I know enough to stay away from the mains/high voltage sections). Is there a way to find a local wiz to help learn how to troubleshoot it? I'd love to learn the ropes, but I don't want to get in over my head without some kind of lifeline! |
