Schematics for isolation tester Metriso 500 VW?

[nightfire]

My recent akquistion is an isolation tester from the past, around 1980 I would guess:
https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg4230262/#msg4230262


Another guy has made some better report and pics from his version:
http://www.crowave.com/blog/2017/06/25/metriso-500-vw-bbc-metrawatt/


Situation: The tester came quite complete in good condition to me, and as far I have measured its behaviour, it is in perfect working condition.
This means, it could use some good cleaning, replacement of the rubber foam in the battery compartment that is actually getting sticky, and some Deoxit love for the contact surfaces of the probe tips is probably also no bad idea.
On the inside there are some electrolytics and tantalums, that probably also would profit from some planned replacement- and now the trouble starts: In the manual (which doubles also as some sort of service manual) are some principal schematics inside, so that the user is able to really understand the way the device works, but no detailed schematics in which the caps etc. are present.

So questions at this point:
- Does anyone has some idea where to get the detailed schematics for the Metriso 500VW? Other versions sadly are not that similar in the internals...
- Some proven tips to replace the sticky foamy thing in the battery compartment? Resp. with which stuff?
- Any tips or caveats to look for when cleaning the probe tips from years of muck and possible traces of corrosion?

[HighVoltage]

It is very difficult to find any Metriso schematics on the internet.

But these older instruments are relative easy and you can trace the tracks and make your own schematics for the area of interest,

[nightfire]

*Sigh* I see, that I am also probably out for some adventure, and this time I really had a look at the manual before buying it and was like "Hey- cool old stuff, where they provided some schematics"

What I am afraid of the most, are the diodes of the push-through type, if they break or go bad...

The rest seems pretty standard to me, maybe except the DC/DC converter stage where the 660VDC is generated.

Other question: What reputation do old Roederstein capacitors have? From the looks of it, the big 1000µF cap is an old Roederstein, anyone with experience with them?

[shakalnokturn]

I doubt your 1mF capacitor is one but if you have any plastic encapsulation ROE radial elecyrolytics they're usually dry.