If it's not working right...then don't use it. Last thing you want is to magnetize the heads more, and then not be able to demag them.
I might get some opposition to this...but frankly, I think the need for demagnetizing can sometimes be overstated. To just demag on some set time schedule may not be the best approach, as some people seem to do.
Use a magnetometer to check the Gauss levels at the heads and transport (you get one with the R.B. Annis kit). If you are seeing anything under 1 Gauss needle deflection from your "normal" position as you bring the meter/probe next to the heads...then don't degauss.
I usually see less than 1/2, and running the demag does NOTHING, as that is probably just the overall magnetism of those metal parts due to the earth’s magnetism in my area.
Straight from the engineers at R.B. Annis :
1 Gauss and over, it's time…over 2 Gauss, your heads/transport are now retaining heavier magnetism.
But if you have less than 1 (or less than 1/2, like I do)…demag one time and check it again…if you see NO change, then that is constant magnetism from the earth on your metal parts…and you will never be able to remove it, so don’t just keep demagnetizing…’cuz you can do more damage than good!!!
You first need to know what “normal” amount of magnetism is coming from the earth that is affecting your metal parts, and then see how much deflection from the “normal” position before you demag.