Keysight 2000X rotatry encoder bad - Page 1
Forum section: electronics / repair

author: HighVoltage
author_rank: Super Contributor
timestamp: June 26, 2022, 12:34:53 pm
content: This Agilent branded DSO-X 2002A scope was bought broken.I fixed the power supply and now the scope is working well so far.However, all large knob rotary encoders (push-able) are very bad in reaction.So, I want to replace them.Does anyone have an idea of where to get them and what is an alternative part number?All the small knob encoders are working well.Maybe the problem is not the encoder?

author: xrunner
author_rank: Super Contributor
timestamp: June 26, 2022, 12:46:14 pm
content: Spray Deoxit into the encoder and turn the shaft back and forth, might just be dirty.

author: HighVoltage
author_rank: Super Contributor
timestamp: June 26, 2022, 01:07:57 pm
content: I tried that, that is why I had it apart and it did not work.Maybe I have to take the encoder out and open it up so the Deoxit will reach the inside.But I rather replace them with a new one.

author: xrunner
author_rank: Super Contributor
timestamp: June 26, 2022, 01:22:33 pm
content: Quote from: HighVoltage on June 26, 2022, 01:07:57 pmIf you are considering replacing it then remove it now. Then check the encoder pins as per proper continuity, you can look up diagrams of how the pins connect inside as it rotates. If it doesn't work douse it again with deoxit and check once more. Then if it doesn't work per that understanding order new part.If it does work then problem is elsewhere.

author: voltsandjolts
author_rank: Unknown
timestamp: June 26, 2022, 01:27:29 pm
content: No markings anywhere on the encoder, underneath perhaps?How many detents?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: June 26, 2022, 03:27:56 pm
content: You can use a scope to check it, supply power, connect to one terminal and turn the knob You should see nice square waves. Connect to other terminal to see if it the same.However these things are cheap and since you have the board out perhaps just buy one and install it.Looks like five pins. two for supply power and the other three are forward, neutral and reverse pulses. No big deal. anything you find with these connections should work.Two more connections are just for the metal base.I think the supply voltage is usually the sameI bought a few on ebay yrs ago and use them in various applications with good results

author: Per Hansson
author_rank: Unknown
timestamp: June 26, 2022, 05:09:00 pm
content: Bourns has a large selection:https://www.bourns.com/products/encoders/contacting-encodersHere an example:

author: Someone
author_rank: Super Contributor
timestamp: July 15, 2023, 05:16:25 am
content: Had a few of these encoders start becoming inconsistent and finally got around to fixing them today. Didn't bother identifying the parts but they didn't exactly match any of the Bourns/Alps/Panasonic encoders I'm familiar with.Desoldered from board, pried open the encoder assembly and cleaned in flux cleaner + lubricated the contacts with MG chemicals 801B, then pressed the assembly stack back together and reinstalled.There was the usual build up of dust etc which makes encoders stop responding, jumpy, or inconsistent (be they electrical or optical types). All back to smooth and predictable controls now