Identifying trimmer capacitors

[NilByMouth]

Hi,

I have an old Acorn Electron floppy drive controller that's suffering from a bit of corrosion. There's a small yellow trimmer capacitor next to the crystal with no markings on it. The plates are green with corrosion so I'd like to replace it. Is there a way to identify its value? It looks a bit like a Vishay 65pF.

Thanks
Malc

[daedalux]

For what i know. And i not shure how much of an standard this is.

In ceramic trimmers. I think this complies for some tht Murata and no name ebay ones.

blue 2,7 to 10pF
red  4,2 to 20pF
green 5,2 to 30pF
yellow 6,8 to 45pF

In polipropilene i can see the values are different but the order is the same more or less. The one i can access to is yellow 5,5 to 65pF

This plastic trimmers are lots of times resetted and fixed by turning them and then leaving in the original position as the insulation is so thin and flexible.

[NilByMouth]

For what i know. And i not shure how much of an standard this is.

In ceramic trimmers. I think this complies for some tht Murata and no name ebay ones.

blue 2,7 to 10pF
red  4,2 to 20pF
green 5,2 to 30pF
yellow 6,8 to 45pF

In polipropilene i can see the values are different but the order is the same more or less. The one i can access to is yellow 5,5 to 65pF

This plastic trimmers are lots of times resetted and fixed by turning them and then leaving in the original position as the insulation is so thin and flexible.

Thanks, I'll try the Vishay one I saw - it has the 2 pins at 45 degrees like the one that's on the board. It may not even be faulty - I just hate seeing corroded components on a board.

Malc