Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: legg Newsgroups: sci.electronics.repair Subject: Re: Owon PDS 5022S Date: Fri, 16 Aug 2024 09:42:13 -0400 Organization: A noiseless patient Spider Lines: 79 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Fri, 16 Aug 2024 15:41:50 +0200 (CEST) Injection-Info: dont-email.me; posting-host="3c2df61c57a84a9789bc891d16450515"; logging-data="1537763"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+ACw0Rxk5rUH1ksY4eQynW" Cancel-Lock: sha1:Yq5p9AigTP7kCLZ2zGSzSH14cH4= X-Newsreader: Forte Agent 4.2/32.1118 Bytes: 4364 On Thu, 15 Aug 2024 20:34:51 -0700, Jeff Liebermann wrote: >On Wed, 14 Aug 2024 14:26:48 -0700, Jeff Liebermann >wrote: > >>A few years ago, my Owon PDS 5022S oscilloscope failed with a strange >>looking display. See photo at: >> >>From what is visible on the display, everything seems to be working >>except for the strange display. Whatever is wrong is probably in >>either the color LCD display or the circuitry that drives the display. >>Does anyone have a clue what might have failed? Mostly, I'm trying to >>save time fixing it. (I haven't torn it apart yet). >> >>User manual (no schematic or block diagram): >> >>Specs: >> > >Video of a Digimess DS25 DSO, which is similar to my Owon PDS5022s: > >The plastic case, front panel, and oscilloscope section are identical. >However, the LCD panel, power supply and backlighting inverter are >very different. > >More videos: >This PDS5022S video is 14 year old with upgraded firmware: > > >More of the same: > (same problem as mine) > > > > (shows defective LCD) > > (shows defective LCD) > > (looks similar to mine) > > > > > >Some photos of the internals: > >When I removed the cover, I was immediately hit with the distinctive >smell of burned resistor. I tried to find the source with my nose, >but failed. When I "fire" it up again, I'll do some more fault >"sniffing". > >Visual inspection didn't find anything that looked like a problem. I >tested all the electrolytics with an ESR tester. I did another visual >inspection with a microscope: > >No problems found. > >I think it's the LCD panel. There are replacement LCD's on Ali >Express and eBay for about $140. However, the scope is selling on >eBay for about the same price. > >This one has the same problem as mine: > > >If the DSO doesn't magically fix itself in the next few days, it's >going to the local recycler. They're doing no-one any favors by making service info and replacement parts unavailable. Even so, stocking lcd displays for ten year gone product is probably asking a bit much. Imagine if they did? There's nothing particularly special about their circuitry, that needs protection. It's all in the firmware. What needs protection is the end user. RL