RIGOL 1052E DSO (Part 3)

Part 123

Erratic clicks!

Life goes on and the Rigol 1052E remains a reliable companion still purring and always ready to help diagnosing circuits and running prototypes testing. Sometimes ago, I experienced some strange changes in time and amplitude scales when using the notched rotary encoders. Values where jumping erratically from one value to an other, whatever the rotational speed of the knob.

I quickly found some papers on this subject. All posts are pointing to the rotary encoders themselves (I could have been worst, like firmware problem). Some suggest to disassemble the rotary encoders, some suggest to replace them. I decided to investigate the problem by my self and the next pictures illustrate the steps to the suspect components. Firstly, you will need to open the oscilloscope enclosure, as described in a previous post. Next we will need to remove few more screws in order to get access to the dashboard.

There is no need for disconnecting any cable during this procedure!

Remove the four screws which retain the power board (3 small, 1 larger screw)

ds1052e_04

Remove the two screws and nuts which retain the power cord socket

ds1052e_03

Then remove the 3 screws retaining the corners of the front plastic cover

ds1052e_01

After pulling the power card apart, remove this other screw

ds1052e_02

And this other central screw

ds1052e_05

Take the front cover apart and get access to the dashboard

ds1052e_06

All encoders are from ALPS. From my experience, these are good reliable components and I use in some of them in quite rough conditions without any complaint to make. So, how come they get defective? As in many other cases looking alike, I simply used a contact cleaner spray, right through the little slits which are visible between the black and the green parts of the encoder bodies.

ds1052e_07

After doing this and exercising the knobs again, I felt that the clicks where more “firm”, more clicking than before the cleaning, just like if some grease from the shaft migrated to the contact area. I performed a real life testing before reassembling the parts and the problem looked like it had disappeared. Putting every thing back in place did not change the RIGOL 1052’s mind and this good ol’friend is now back to operation without this pretty boring false stepping problem.

HTH

Leave a Reply

You must be logged in to post a comment.