One of our favorite new tools has taken some damage. The scope on the east bench has had two of four channels blown. The damage is something that we can repair ourselves at little cost and we can learn a lot by doing it, so I’m calling this “actually good news”.
It’s good both in that we have an opportunity to gain experience and perhaps make classes of it, and also in that it provoked us into investigating how repairable our oscilloscopes actually are, and I think they look nearly as repairable as HP and Tek back when they still published their schematics. These scopes use available parts mostly, including and importantly in the discrete frontends and sampling. Further, the popularity of this scope has led to the community producing schematics.
My feeling is that this is a great scope for us to continue to standardize on, as our ability to maintain them appears very high. We need not fear irreparable or costly damage if an errant member should happen to do something like probe the output of a 5kV electric cattle fence transformer on channel 1 and then again on channel 2 (for example). I believe we can repair this in-house, and even become proficient at it.
The goal is not simply to restore the scope to working order, but to take advantage of this opportunity for the membership to benefit from the experience of repairing one of our own tools. Further, considering that our ability to repair these scopes is thanks in large part to the availability of the community-produced schematics, we have an opportunity here as a part of that community to contribute the documentation of some of the diagnostics by discussing our findings here on this public forum where they can benefit many googlers for years to come.
So far we’ve established that two channels were damaged enough to not show a signal. Myself and @TBenV disassembled it and we did some initial troubleshooting and took some photos, and I’m preparing a post to document our findings and current status which I’ll post shortly. I’m out of town and I think @TBenV has taken charge of the repair efforts (by that I mean I voluntold him and he didn’t protest) so if you see him around the space, he’s the one to talk to about it.