Buying replacement rotary encoder for DS1052/1102E scope - Page 1
Forum section: electronics / testgear

author: tom66
author_rank: Super Contributor
timestamp: February 09, 2014, 06:58:50 pm
content: I have a Rigol DS1102E with a broken trigger encoder; I've disassembled the unit (amazingly, without voiding the warranty sticker, which came off cleanly...) but am having difficulty locating a replacement encoder as the original part does not have any part #.Ideally, I'd source the part from Farnell as I live close to the Leeds trade counter. I've seen some parts on Itead / Seeed Studio, but I'd have to wait weeks to get them and the scope is already disassembled (perhaps I would have been wiser to check first, but hindsight is a wonderful thing.) Also, they are for the volts/timebase dials, which have a detent on each event. The trigger level and other controls are freely moving without a detent.Perhaps if I can find an original part #, I can source a replacement equivalent or near-equivalent part...Any suggestions?

author: georges80
author_rank: Frequent Contributor
timestamp: February 09, 2014, 07:12:19 pm
content: Quick search on digikey for rotary encoders for something that "looks" like your picture, found this:http://www.digikey.com/product-detail/en/EVE-GA1F1724M/P10859-ND/286883Maybe look around digikey, though the above item "looks" close...cheers,george.

author: JDubU
author_rank: Frequent Contributor
timestamp: February 09, 2014, 07:18:21 pm
content: Wouldn't that be covered under warranty?

author: tom66
author_rank: Super Contributor
timestamp: February 09, 2014, 08:24:51 pm
content: Quote from: JDubU on February 09, 2014, 07:18:21 pmYeah. That's a long story.The knob/shaft had always been a little loose/wobbly, and I'd never really complained, but one day, it basically broke cleanly in half. I guess it gave in! I took out the rest of the plastic so I could use it with a screwdriver. MCS and/or Rigol considers it "wear and tear" and thus not covered under the warranty, which has over 1.5 years left today. I think the unit might have been dropped in shipping as the box was quite beat up when I got it.Also, the storage button LED has always been intermittent. I'll touch up the solder on it and/or replace the part completely to see if I can fix it.After all this, I'll probably sell the scope on as a repaired item for cheap on eBay or here. Will probably get a DS2072/DS1074Z or save up for a 2000X series. And I'll thoroughly inspect it beforehand to see that an issue like this won't creep in again.@georges80 thanks I'll take a look. I don't know how many pulses/rev the Rigol encoders give; if only I had a 2nd scope to check! Though, I doubt it will be a major issue. It'll just make trigger setting faster or slower. The other concern is phase; the encoder might work the other way when turned... there's no standard apparently. If so, I'll have to do a little rework on the PCB to swap the A and B connections.

author: matkar
author_rank: Regular Contributor
timestamp: February 09, 2014, 09:14:46 pm
content: It seems they are ALPS brand EC12 standard series:http://www.alps.com/WebObjects/catalog.woa/E/HTML/Encoder/Incremental/EC12E/EC12E_list.htmlThe thing is standard series don't have integrated pushable button. It shouldn't have detent, so the last three ones are the closest match. There is a green plastic thing seen under the encoders on your picture. Is that part of encoder or perhaps a button underneath? Desolder it and let us know.

author: tom66
author_rank: Super Contributor
timestamp: February 09, 2014, 09:46:40 pm
content: The button is built into the encoder. The two bottom pins are normally open contacts for the button. I suppose it's not impossible to imagine it's a custom part for Rigol.

author: matkar
author_rank: Regular Contributor
timestamp: February 09, 2014, 11:47:49 pm
content: An alternative would be to buy an EC12 encoder and change the broken shaft on the original one if only that's what's wrong with it.Or ask if anybody has a broken unit and is willing to sell you a spare part.

author: tom66
author_rank: Super Contributor
timestamp: February 09, 2014, 11:59:32 pm
content: Icould probably live with detent, but if I'm going to sell the scope on, it needs to be as original as possible. Of course, the buyer would know it's repaired, but it still needs to feel like the proper control.The closest alternative parts I can find are in the ALPS EC11 series or Bourns PEC11 series.The EC11 with no detent, metal shaft, 18pulse/360deg and 20mm shaft length is a close match.http://uk.farnell.com/alps/ec11e1830401/encoder-vertical-11mm-0det-15ppr/dp/2064983?Ntt=EC11E1830401It's £1.29 and stocked, so a cheap part. I'll have to check if 20mm will fit. If not, I think there's a 15mm part.Not sure if the originals are 12,18,24 or some other number, but that difference isn't as significant as detent (which would be really off putting for a trigger level, IMO.)

author: matkar
author_rank: Regular Contributor
timestamp: February 10, 2014, 10:51:02 am
content: By turning the knob for one revolution the trace on the screen makes 96 steps (pixel movements). So it is a 24 pulse version.

author: tom66
author_rank: Super Contributor
timestamp: February 10, 2014, 11:38:31 am
content: Thanks for that info, so I'll try to source the 24 step version.