[ben]

The problem is, very often you need to look at the whole tape path, as one adjustment is often dependent on others being correct. Entry and exit guides, and their travel/endstops. A/C head, then there are things like clutch and pinch roller which can also affect the 'tracking'. Then if someone's been twiddling there are things like FM level and head switch point.

In your case, you had noise both at top and bottom of the picture, that suggests someone may have been 'at it'! It's not very usual for both guides to go out of alignment together.

Incidentally, if a machine has been diddled with, you can often get an initial 'ballpark' adjustment by using a pre-recorded tape from a well known production company (not kids' cartoons as these apparently often used B grade tape), watching if the tape wrinkles on the lower drum and adjusting the guide back from there. That should at least get rid of the multiple fixed noise lines. Then its a case of greater precision adjustments (/test tapes /scope) and finally centring the tracking control with the A/C head.