I decided to see how the VU meter on the front of my hi-fi comes apart today. I started on the second QX-747 because the meters on it weren’t too bad.
Pulled the lid and front panel off. Prised the green scale out.
Prised the shadow board out.
That left me with a big old bucket with some silver bits in. That’s not the way in, then. Not all lost, the shadow board was a bit grimy on the back so that was cleaned up with a soft cloth.
There’s a big fixing screw hidden in the back. Undid it carefully after pulling the entire meter assembly out.
That let the front come off and showed the movements. Small silver pieces attached to moving-coil motors. You can see how they rotate there and let the light shine through the small aperture towards the shadow board.
Tiny little hair springs.
Removed the light board from the back. The bulbs were grimy.
They did all work so set about cleaning them with Q-Tips.
There was quite a lot of dirt stuck to the bulbs. Not sure what all of it was, perhaps the remnants of old colored filters.
Glass came up clean and clear.
Reassembled the fiddly screws that I managed to drop several times into the case.
Brightness of each is good and even, the idle position of the lights leaves a little to be desired but the adjustment levers (same as you find in a wristwatch) are glued. I might try heating the glue up with an iron to see if it softens on the other set.
They all move nicely though, brightly lit.
Looks okay with the smoked plastic of the front panel to add a bit more contrast. Shall do the other set now I know how to take it all apart.