Log entry time 11:56:51 on June26,2004

Entry number 126952

While Mark was working with the septum magnets, I tried to find the problem with the left profile scanner's y (long) axis.  The y signals had been very irregular, very nonlinear in relation to the encoder values, really noisy, far smaller than they should be, and affecting the reference voltage signal.  I found that the capacitor was connected to the y reference voltage cable, so I moved it to the reference voltage output.  I noticed that the potentiometer grounds were sometimes making contact with a screw on the pot, so I taped the screw and the grounds.  I replaced the cable between reference voltage and the y pot.  The y pot grounds didn't look perfect, but they should be functional.  I suppose it is still possible that the ground connection at this point could be affecting everything, although it looks like it should be functional.  I taped the chunk of connectors, and verified that input was coming from the circuit box, and output was going up to the ADC.  i quickly looked at the x pot, everything there looks fine.  I put a t connection with a terminator on the y pot input cable in case there was an impedance problem.  This didn't seem to change anything, but I left it in just in case.  in the end, the signals looked about the same.  we need a new potentiometer.  again.