Simpson 260 series 6, Z/A (zero adj.) screw?

[onesixright]

Hi All,

I got a Simpson 260 series 6, looks awesome 

On arrival it made some weird noise, like something was loose inside So i opened it up to see what was going on.

In the battery compartment i found a small piece of bakelite, not sure where it came from  . But then, there was more (sounds), so i opened the backside, but nothing came out. Still a weird sound, coming from behind the glass.  Carefully removed the glass, and ta-da! a small coper washer, that was ment to keep the glass in it place. So i cleaned the glass and put the thing back together (all good), but i'm now question how to deal with the Z/A screw?

I moved the "fork" on the meter carefully in the center (pointing down), and then turned the Z/A screw straight up. Put it together and tried it. Needle does move, but it doesn't feel right. I also tried to turn the peg straight down, but didn't feel it was any better.

I got two questions:

1. How should the Z/A screw be positioned? Any handy tips put this back together (its very hard to see)?

2. When / how do you actually use the Z/A screw?

Thank you!

[dacman]

If you are referring to the mechanical zero screw for the meter movement, place the meter face up on a work surface, and adjust the mechanical zero adjustment until the meter is over 0 on the left.  You should be able to turn it 360 degrees.  Turn the screw in a clockwise direction, come up from below 0 and when the pointer is over zero, back the adjustment up a few degrees to disengage.

[Gregg]

Here is a nice youtube video about it: about 10 minutes into it it covers the adjustment screw little bit.  Basically the post on the screw must engage the slot of the movement adjustment arm.  You should be able to see the meter needle move both ways as you turn the screw back and forth.  If it won't zero even with the post engaged, you  may have a messed up hair spring in the movement.  there are two hair springs that act to carry current to the coil and to return the needle to zero; these sometimes get the tiny filaments tangled a bit from a drop or something like the loose washer getting inside and may be able to be untangled if done very carefully.  There are a bunch o youtube videos showing analog meter movement repair. 
It is nice to know that analog isn't dead, yet.