Tach acting strange??
 

My Gaffrig 8,000 RPM tach with the Memory switch "TACH / RECALL / ERASE? is not working well. Sometimes works fine, most of the time goes up to around 1,500 and just stops there.

If I move the switch around, you can see the needle move freely, so it does not appear to be physically touching inside.

Checked the lines to see if a contact was loose, nothing.

What can I check for?

If it IS the tach, how can I test that?

Any suggestions??

Thanks!