API 525 Compressors - Sticking VU meters

Guys,

A friend of mine has a couple of API 525 compressors (probs around 5 years old, and deffo out of warranty)

The VU's are sticking. Half way down.

What is the best way to tech these? Can they be 'oiled' or is it more complicated than that.
I'm a half reasonable tech, but can I attempt a repair on these
Is there anywhere in the UK to get replacement VUs?
Is this necessary?

What do you guys suggest

Cheers Matt

You would want to check for corrosion or other blockage of the movement first.  Does the movement freeze when powered off?

Remove the modules to move and rotate them physically while watching the needle.  Does it move freely or get stuck?  A sticky needle indicates corrosion; a free-moving needle indicates meter circuitry causing the freeze.
There is never any oil required in a meter.
Those are tiny little meters, so if you determine its a physical problem then just replace them.
Mike