Tascam 488 Rec/Play head adjustment

[yetipur]

Hello I've been getting some sound dropout on my tascam 488 mk2. I know it is happening when I record, as opposed to playback, because the dropout will be in exactly the same spot (like a certain snare hit for example). After ruling out head cleaning and demagnetizing,
I took it upon myself to adjust the tiny rec/play head screws which move the head closer or further from the tape path(up and down), or side to side (horizontally). I set it to where the highest output of playback sound was possible. It still has the dropout of sound, although not as bad. Does anybody know why this happens or is having similar problems? Is the head worn out? Is there a calibration procedure? Thanks in advance for your help.