Lazarus wrote:

At this location on the PCB you will see one or two small screws which are
variable resistors.....turn them until your current discs play

But be warned you may now have problems with your older discs!

No. This is a very bad idea.
There is an actual procedure in the service manual for doing an alignment.
It's not all that hard, and all you need is a reference disc and a scope.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."