Rigol Trigger Level

[wd5gnr]

I got the 1052E back when the hacking took off. When I first got it I noticed that sometimes the trigger level knob didn't want to move the trigger level much, but then it would work later so I always assumed there was some setting that was locking my trigger. But now it has gotten worse and just barely jiggles around some center point. Of course, you can always zero it or 50% it but that's not always good, especially in single shot.

1) Anyone else see anything like this which would imply its a firmware/software thing?

2) If it is the encoder, anyone know what kind they are or if they are cleanable?

[rossmoffett]

It's the encoder, other people have posted troubles with this in only the last couple of weeks.  Don't recall the part number, dig through the forum a bit.

EDIT:
https://www.eevblog.com/forum/index.php?topic=1245.0

[RayJones]

Before you jump in replacing a servicable part, I have noticed that there is a deadband / snap function about 0V when adjusting trigger level.

You need to turn the knob a fair bit to release from this zone...
Quadrature encoders either work or don't work, and the number of turns required to release from the deadband would not suggest a faulty encoder unit.

[wd5gnr]

Yeah that's the "sticky keys" feature (you can turn it off). This isn't that. It does act a little like it is being "pulled" back to whatever value it is set at. But it does it at all values. And it used to do it intermittently.

I've seen shaft encoders fail like this before. The Kenwood TS570's mutich knob gets sticky like this and requires rapid rotation to "clear" it. Not sure what the failure mechanism actually is. If they are mechanical shaft encoders, could be corrosion on the grey code "plate". If it is optical its harder to imagine. Maybe gunk in the little slotted wheel?

[alm]

I don't think Rigol uses optical encoders. They are significantly more expensive and more durable. Probably cheap mechanical encoders, so cleaning the contacts might help (if you can get to them), for example flushing them with IPA if there's no lubricant.

[Mechatrommer]

I don't think Rigol uses optical encoders. They are significantly more expensive and more durable. Probably cheap mechanical encoders, so cleaning the contacts might help (if you can get to them), for example flushing them with IPA if there's no lubricant.

i can pretty assure this that 95% probability that its the mechanical encoder, as i've opened the board and inspected the encoder, the one similar to variable resistor (potentiometer) shape.

[wd5gnr]

Well I broke my warranty seal. What a bear to get into. The instructions elsewhere were helpful. Unfortunately I ran out of time before I could get into the front panel so I put it all back together. Well except for the screws under the handle which seem to be hard to start.

Anyone have a part number for an equivalent encoder? If I do get the rest of it apart (I stopped before removing the fan and power supply) I am going to fix it before I button it back up one way or another way.