Did B&O ever use those infamous black & white Piher trimpots?

I just finished otherwise repairing a BM5500 which has these at the idle current settings, and I'd like to know if they have been replaced already. The solderings look original, unlike some other places...

These ones?

http://www.segor.de/bilder/0000bf54.jpg

I've never seen them on a original B&O board...

But why are they "infamous"?

Exactly those. So they have most probably been replaced already, I'll just let them be.

Over here they don't have a reputation of being too reliable... but it might be just hearsay, they always worked for me.

I have seen some. Beomaster 5500/6500 springs to mind but I've also seen them in TV's.
Though they were always for standard tiny Philips screwdrivers, rather than hex.
I've probably replaced a few but never had much trouble with this type particularly and wouldn't worry
about mounting new ones of the same type.

Martin

Mika,

I've been using these for years with no problems. I use them specifically when adjustment must be made through a hole in the PCB from the foil side (ie - no access to the component side). All my restorations of the BG 4002, 4004, 6000 have been with these.

If there is access from the component side, then I use the Bourns 3352E Cermet trimpots.

Menahem