Tek 2465B - mains filter smoked

[ppppenguin]

Sitting quietly at my desk and I hear an odd noise. Probably the blind flapping at the open back door. Walk over to the door and there's a burning smell. Hurry to turn off main isolator on bench. Have a good sniff around, turn off most kit separately and start powering up. The two PCs on the bench didn't much like the sudden shutdown. The XP one is OK but the W98 one is sulking.

It's soon very obvious that the culprit is my beloved Tek 2465B. It's equally obvious that it's the mains filter. Standard fault. Open it up, which is tedious. There's brown gunge by the voltage selector. The mains filter is still warm. Fuse in plug has blown.

I think it will have to live without a mains filter for now.

Rather better than the mains filter in my Tek 1755A Vectorscope which got hot enough to melt solder before taking out the bench RCD.

[ppppenguin]

The brown gunge by the voltage selector hasn't come from the mains filter. No idea what caused that.

[ppppenguin]

I found a Belling-Lee filter in my spares box and fitted it. Scope now works again. I seem to have a screw left over

[Diabolical Artificer]

RIFA cap? Blue Oyster Cult were wrong.

Andy.

[ppppenguin]

I don't know what Schaffner put in their filters. I'm not cutting it open to find out.

Looking more carefully I think the brown gunge came from the filter.

[Nick]

I don't know what Schaffner put in their filters. I'm not cutting it open to find out.

Looking more carefully I think the brown gunge came from the filter.

It does. Standard fault and the Schaffner parts are still available.

[radioman]

Well that's a coincidence.... I was using my Tek' 2445A last week when it decided to go 'pop' and start issuing smoke - it was still working when this happened but I decided it would be safer to switch it off...
I suspect that there'll be a Rifa cap in it somewhere but I've not opened it up yet to check.

Andy

[chriswood]

I have had many of those Schaffner iec input connectors fail with the brown goo leaking out. I suspect they may either use Riffa caps inside them or at least the same technology. In an emergency I have carried on using the device until a spare is available, and I have seen them in second hand test gear I have found a few which had obviously let go many years ago but just carried on being used.
They clearly lead a stressful life if equipment is left plugged in even if they are off on the switch on the unit. At least they seem to fails safe other than the smoke and awful smell.