I’m rebuilding a HP 412A and nearly done. There is a Sprague 192P film cap that is in the switch and in a place that would be an absolute pain to swap out.
This is what it looks like
It’s a 200v rated cap and I’m guessing it doesn’t see a whole lot of voltage I the switch.
So not being stressed, would you think this cap would be perfectly fine? Or are these well known to degrade like bumble bees or black beauty (well the paper ones) and I should take the 2 hours to remove it and swap it out? I know there are polyester films that do go bad like the flat grey ones used in Marantz, those are notorious for failing.
Thank you,
Dan
This is what it looks like
It’s a 200v rated cap and I’m guessing it doesn’t see a whole lot of voltage I the switch.
So not being stressed, would you think this cap would be perfectly fine? Or are these well known to degrade like bumble bees or black beauty (well the paper ones) and I should take the 2 hours to remove it and swap it out? I know there are polyester films that do go bad like the flat grey ones used in Marantz, those are notorious for failing.
Thank you,
Dan
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Film caps rarely go bad and when they do it’s often an internal short. If the case is in good shape the cap is fine if it measures right. Don’t worry about it. Spend time on electrolytic caps and carbon comp resistors. They are your failure points in old equipment.
Thank you for the response. I have all the carbon resistors swapped with 1%ers, many were way off. I also replaced all of the electrolytics and paper caps like the bumble bees.
The unfortunate thing is I can’t measure this one, I can’t get to the other side of it. If I’m going to measure it maybe it makes sense to just swap it, but it people think it likely measures fine I’ll save myself the trouble of tearing out the front cover and removing the large multilayer switch. If people think that it’s best it gets measured then bummer, lol, but I’ll do it.
Dan
What makes sense is to determine whether the unit is performing correctly or else has a problem that you can positively sheet home to this specific component. It doesn’t.
Good call. I’ll leave it for now, calibrate and go from there. Basically I’m trying to determine if anyone knows if or has run into one of these series in some point of failure. If so I’ll want to take of it now. But if nobody has heard or seen such things then it’ll likely stay.
Dan
Dan