Re: Tek TDS500/600 series scopes capacitor replacement best practice

saipan59 (Pete)

A related cap story from just last week:
I was checking out a Yamaha A-700 hi-fi amp (circa 1984) which had not been used in many years. Opened it up to clean out dust and such, and noticed 3 or 4 vertical electrolytics had some hard, brownish 'stuff' apparently leaking out of them. This seemed odd, so I unsoldered one from the PCB and examined it closely. Nothing wrong with the cap. Turns out it was a 'glue' put there in manufacturing - it was only seen under the somewhat larger vertical caps, so I suspect it was for mechanical support. But it had actually caused some corrosion on the leads of a couple of nearby resistors, so I scraped those clean.
Re-installed the cap. The amp works perfect. Very nicely built, rated 100W/ch, 0.005% THD. Has an "Auto Class-A" button which puts the output stage in class-A when the signal level is less than a few watts. Of course, the amp then generates a lot of heat while doing nothing... I'm not clear on who has ears (or speakers) good enough to hear the difference.


Join to automatically receive all group messages.