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From: legg <legg@nospam.magma.ca>
Newsgroups: sci.electronics.repair
Subject: Re: Owon PDS 5022S
Date: Fri, 16 Aug 2024 09:42:13 -0400
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On Thu, 15 Aug 2024 20:34:51 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>On Wed, 14 Aug 2024 14:26:48 -0700, Jeff Liebermann <jeffl@cruzio.com>
>wrote:
>
>>A few years ago, my Owon PDS 5022S oscilloscope failed with a strange
>>looking display.  See photo at:
>><https://photos.app.goo.gl/rYGeaGygSMXHtMCb8>
>>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):
>><https://www.saelig.com/downloads/pds5022s.pdf>
>>Specs:
>><https://www.batronix.com/shop/oscilloscopes/digital-oscilloscope-pds5022s.html>
>
>Video of a Digimess DS25 DSO, which is similar to my Owon PDS5022s:
><https://www.youtube.com/watch?v=yfjh0KDEaTY>
>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:
><https://www.youtube.com/watch?v=JQtvW1wpl6w>
>
>More of the same:
><https://www.youtube.com/shorts/6OCnuXpM2mY>   (same problem as mine)
><https://www.youtube.com/watch?v=M0galCMhm7U>
><https://www.youtube.com/watch?v=nydo6xsLY7g>
><https://www.youtube.com/watch?v=hzZpE9yrMKA>
><https://www.youtube.com/watch?v=UInlOkFDf24>  (shows defective LCD)
><https://www.youtube.com/watch?v=X1OTPt7_1Z8>
><https://www.youtube.com/watch?v=1sUGiwaEjq8>  (shows defective LCD)
><https://www.youtube.com/watch?v=xHaapgrXxYI>
><https://www.youtube.com/watch?v=escwIX0vY64>  (looks similar to mine)
><https://www.youtube.com/watch?v=EQXzP6sazaA>
><https://www.youtube.com/watch?v=MNzaAPetnVw>
><https://www.youtube.com/watch?v=K3mITKGuAW4>
><https://www.youtube.com/watch?v=bjRQP8mDCV0>
>
>Some photos of the internals:
><https://photos.app.goo.gl/ZgCRUB4SChDYRrRy6>
>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:
><https://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/SZ30-01.jpg>
>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.
><https://www.ebay.com/sch/i.html?_nkw=owon+pds5022s>
>This one has the same problem as mine:
><https://www.ebay.com/itm/285811299516>
>
>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