Paco S-55 Oscilloscope (Smelly Failure)

[Cyberdragon]

I was tracing down a fault in a stereo when I noticed a funny smell. At first I though the faulty component in the amp was about to blow. Then I noticed the oscilloscope screen was all fogged up. I dismissed it as humidity for a second then I realized...

*sniff-sniff*
FOG=MAGIC SMOKE! so I unplugged it. But noxious fumes were realesed! (Ewwww!) Capacitor?

I'll assess the damage once it airs out a bit. Hopefully it's not to bad like a fire, but there might be a nasty electrolyte spill.

[oldway]

Paco S-55 oscilloscope = tube oscilloscope from....1955 
Nothing surprising, it may be time to replace some capacitors.

[Cyberdragon]

Someone before me has already replaced some of them, there are orange film caps inside (unless these are original). Not sure about the filters, can't tell if they are restuffed.

Oddly enough, couldn't find which one vented if it was. There was no sign of any damage, except the transformer was still warm nearly an hour later . Something must have caused an overload, I'll check the filters for leakage, even though I'd expect them to vent before the transformer overheated.

I think the tranny is fine though, it was still working even when smoking.

[vk6zgo]

Some old Oscilloscopes use Selenium rectifiers in the EHT circuit.
When those things die,they don't always show any external signs,but they smell bloody awful!!
( Like the worst fart you can imagine)

[Cyberdragon]

Some old Oscilloscopes use Selenium rectifiers in the EHT circuit.
When those things die,they don't always show any external signs,but they smell bloody awful!!
( Like the worst fart you can imagine)

Nope, this one uses an HV rectifier tube similar to ones in televisions. Didn't smell like sewer, smelled like a horrible accident in a chemistry lab. Like someone mixed shoe polish with fertilizer and heated it.

The HV capacitors are white tubes though, meaning likely paper. Except finding .1uF 1600V capacitors is proving hard, all that comes up are used ones (eeewww). What's the next voltage up? (In modern standards)