Siglent SDS 1202X-E Ch 2: hosed, or is there hope? - Page 1
Forum section: electronics / repair

author: pkube
author_rank: Newbie
timestamp: March 06, 2022, 09:49:28 pm
content: My Siglent SDS 1202X-E scope developed a problem with Ch 2. Reduced sensitivity, and extreme high frequency rolloff. See attached screencap with both channels hooked to the scope's squarewave output.It's not the probe; swap channels, and the problem stays with Ch 2. Both channels set to the same parameters (DC coupled, wideband, etc.)Is there likely a fix, or is this now permanently a one-channel scope?Thanks for any help!--Paul

author: bob91343
author_rank: Super Contributor
timestamp: March 07, 2022, 12:52:28 am
content: Perhaps a switch problem. Something with an attenuator. I don't know the model so first I'd do is get a service manual. It doesn't look hopeless.

author: pkube
author_rank: Newbie
timestamp: March 07, 2022, 05:37:03 am
content: Quote from: bob91343 on March 07, 2022, 12:52:28 amThe service manual downloadable from Siglent is not real helpful. This is the troubleshooting flowchart, attached below.Which may be what I end up doing (replacing the whole main board), but meanwhile I'm hoping someone out there has seen this same problem before and has a cheaper fix.--Paul

author: tautech
author_rank: Super Contributor
timestamp: March 08, 2022, 06:18:29 am
content: Some more info please.Age of scope ?FW version installed ?Please do following:Default scope. Set probes to 1x and connect both to probe compensation output with one of the reference leads to ground.Press Autoset.Press Ch2Take USB screenshot with the blue print button so to not have the Save/Recall menu showing but instead the ch2 menu.

author: MathWizard
author_rank: Super Contributor
timestamp: March 09, 2022, 07:39:57 pm
content: I have the same scope, (4-ch), visually It reminds me of times when I fed a squarewave into the scope, when it was on AC coupling. And least on some time scales, some RC network, I didn't know what was going on, till I switched back to DC coupling and got a nice sqrw again.I'd love to take my scope apart some day, in fact I'll have to soon, to clean plaster dust from it

author: pkube
author_rank: Newbie
timestamp: April 29, 2022, 11:48:53 pm
content: Update and resolution on this problem with my Siglent scope.On March 7, I contacted Siglent USA to get pricing on a replacement mainboard for this SDS 1202X-E. Found out I can't buy a part from them, but I was kindly reminded that my unit was still under warranty. 3 year warranty -- pretty good.I got a RMA and sent the unit in at my expense. Three weeks later I got it back, with thesame issue as before. The warranty tamper seal had been cut, so they had opened the case, but evidently had done no repair. There was no accompanying paperwork or any email communication indicating what work (if any) had been done.I sent email and phoned to try to find out what had happened, and got no information except a claim "the scope was working when it left here". However, after exchange of some words, I got another RMA, and this time a "call tag" for shipping paid by Siglent. Sent the unit in again, and today -- after another 3 weeks -- recived it back, this time with a note "replaced board."And the scope works again as it should.To summarize: Siglent did eventually honor the terms of the warranty and fixed the problem, but it took some time and prodding.

author: thm_w
author_rank: Super Contributor
timestamp: April 30, 2022, 12:23:33 am
content: Quote from: pkube on April 29, 2022, 11:48:53 pmOut of curiosity, how clear were you when you sent in the return of what the issue was? Did you include the same screenshot as here.Funny if they cut the warranty void seal and didn't even bother replacing it with a new one.. and you'd think any sort of basic test they would do would catch the issue.

author: bdunham7
author_rank: Super Contributor
timestamp: April 30, 2022, 12:29:40 am
content: Quote from: pkube on April 29, 2022, 11:48:53 pmThese days that is a clear win.

author: Gordo
author_rank: Contributor
timestamp: April 30, 2022, 04:22:45 am
content: Unfortunately, I seem to be experiencing the same on my Rigol DS1054 (hacked to 1104) scope. The scope is only 5 months old.Unfortunately, I'm in Thailand, and bought the scope in Thailand... Things are "different" here and warranty claims can be a nightmare. I have sent an e-mail to the seller, (who does seem to be a pretty legit test equipment dealer) and have my fingers crossed that they will be able to help. I have no idea who the regional representative for RIGOL is or who is actually responsible for warranty service.Wish me luck, because I think I am going to need it.Gordo

author: pkube
author_rank: Newbie
timestamp: May 02, 2022, 01:55:01 am
content: Quote from: thm_w on April 30, 2022, 12:23:33 amClear written description: "Ch 2 has become defective. The sensitivity is about 20% of what it should be, and a 1kHz square wave looks very, very undercompensated, no matter the compensation setting on the probe. (It is not a problem with the probe; all my probes do the same thing, and they work fine on Ch 1.)"Anyway, I assumed that was clear enough, because I assumed a kind of normal warranty repair process would be in place, where a trouble ticket with that description would be created associated with the RMA, and somebody who knew what they were doing would get assigned to it. These assumptions were apparently not correct.QuoteYep. No more basic test than clipping a probe to the 1kHz square wave compensation output and looking at it.But your point about pictures is a good one, the second time around I included a couple photos of the scope showing the problem and that may well have helped.