hi everyone. wondering if anyone has had these issues and is able to give me something to go on. I would really appreciate any help. I have a proTracker I. The channel A is showing an ellipse in low range 54 ohm, but not in 50 ohms and not in mid 1, mid 2 and high ranges. and also the encoder nub is not working properly it seems. it lowers and adds values at random when turning in the same direction.
You probably have either a bad range resistor, range relay or both are damaged. If the unit is a KJ2 look at R119, R120 and R122. The relays are K4, K3 and K1. ProTracks switch in parallel resistors to get the 54ohms range. It pretty common to damage the low resistance ranges because they are used to test large caps that are sometimes not discharged.
The encoder could just have a bad connection. Inspect the pin connections to the encoder and re-crimp them if possible.
Hello!
Try looking at the encoder signals on an oscilloscope.
Kj2 version U59 ic pin 41 (A signal), pin 42 (B signal).
Kj3 version U12 ic pin 41 (A signal), pin 42 (B signal).
Hi!
Check the presence of the square signal at the output of U14/8pin (KJ3 version).
U14 is an inverting schmitt trigger oscillator, it is a clock signal generator for the encoder circuit.
As said previously on this Forum, and if you haven't done it replace all the 47 uF electrolytic capacitors on the main logic board. They leak electrolyte that does its best to destroy a copper track in the vicinity.
Doesn't cost much to replace all the Electrolytic Capacitors, and these ProTracks are only getting older!
What version of ProTrack do you have there?
to update: the encoder was bad. removed and powered it. on Scope only 1 signal present. purchased a brand new encoder about $100. it was a quick delivery though it was an international shipping. installed and it works like a Charm.
the R88 (1150) and R89 (1000), on channel A are bad and not reading any values.
on channel B the equivalent resisters to R88 is 115 Ohms and R89 is 100 Ohms.
does anyone know the Tolerance and Wattage please?
Hi.
R88 - 115 Ohm 0,75Watt 1% (K5 relay). R89 - 100 Ohm 0,75Watt 1% (K4 relay).
In the 54 Ohm range, 100 Ohm and 115 Ohm are connected in parallel (with K5 and K4 relay contact),
so it becomes 54 Ohm.
Hi
Not sure if this diagram helps for a ProTrack KJ2.
Shows R88 etc.
I'm sorry!
These are the range resistors of a KJ3 version Protrack. R88 and R89.
Huntron Protrack KJ2 showing R88 on attached photo.
Just under the middle section of the C.R.T.
Hi everyone, here is the update: both problem were fixed. thank you so much for all you help and input. unit work nice and sweet, I love it.
replaced resisters 88 and 89, the 54 ohm on Channel "A" is good now.
encoder Problem: while rotating the encoder huntron was not responsive and numbers would jump around. once I got the new encoder, powered both, scope showed original encoder with 1 bad channel. new one looked great on the scope.