Instek GDS-1054B LCD screen flaws - Page 1
Forum section: electronics / testgear

author: wblock
author_rank: Regular Contributor
timestamp: July 23, 2016, 06:27:29 pm
content: Just received a new Instek GDS-1054B from TEquipment. Undamaged, appears to work fine. However, there was a noticeable film of dirt or soap or something on the screen. Looking more closely, and in the right oblique light, I saw these spots. These are actually a bit more prominent in the photo than in real life. The film cleaned off easily with alcohol and a very soft cloth, the spots seem to not be on the surface. There was no shipping protection film on the LCD.The spots don't appear to be visible when the scope is on, but it's hard to tell if this is going to be a problem in the future.I think I recall another recent thread about a similar issue, but was unable to find it.Has anyone else seen this?

author: wraper
author_rank: Unknown
timestamp: July 23, 2016, 06:48:34 pm
content: Quote from: wblock on July 23, 2016, 06:27:29 pmI think that was about Rigol. Return the scope back for exchange.

author: wblock
author_rank: Regular Contributor
timestamp: July 23, 2016, 07:05:45 pm
content: Aha, that was this one:https://www.eevblog.com/forum/testgear/bought-a-rigol-ds1054z-with-a-defective-lcd/Looking at it again, these marks are very different from those, like bubbles in one of the LCD layers.

author: wraper
author_rank: Unknown
timestamp: July 23, 2016, 07:49:57 pm
content: I'd say this has nothing to do with LCD itself. Looks like something wrong with plastic screen protector on internal side or some kind of dirt on it. Actually looks like fungus have grown on it.

author: saturation
author_rank: Super Contributor
timestamp: July 24, 2016, 12:11:07 pm
content: Very interesting. It wiped off? That's good it does look like a mold aka fungus. It happens on flat surfaces exposed to high humidity. If you had checked it with a loupe it could have confirmed it.This happens if the product is shipped without desiccant and it was packed in humid environment. Its harmless so long as its on the outside of the LCD. It will not grow again unless you live in a humid environment and you did not wipe the LCD thoroughly clean.its called glaspilz in German. Its well known to happen in all flat surfaces that are not cleaned regularly but small amounts of white mold are most obvious on glass and all types of lenses.http://www.xtremeplace.com/yabbse/index.php?topic=202388.0FWIW I have the same DSO and its LCD arrived clean and fungus free.

author: nctnico
author_rank: Super Contributor
timestamp: July 24, 2016, 04:23:11 pm
content: I agree with Wraper: return it!

author: wblock
author_rank: Regular Contributor
timestamp: July 24, 2016, 04:33:18 pm
content: Quote from: saturation on July 24, 2016, 12:11:07 pmThere was a layer of some kind of residue on the outside which wiped off, but the splotches are inside the LCD. Like between the front plastic panel and the glass LCD panel.I've emailed TEquipment, but don't expect to hear back until working hours.

author: saturation
author_rank: Super Contributor
timestamp: July 24, 2016, 04:56:01 pm
content: Best if you could repost an 'after wipe' photo and close up of the splotches. Tequipment is very good at customer satisfaction but I'm not sure the return shipping is free; that can be costly. So best to be sure there is likely a problem before going that route.Quote from: wblock on July 24, 2016, 04:33:18 pm

author: wblock
author_rank: Regular Contributor
timestamp: July 24, 2016, 05:22:16 pm
content: Thatisthe after photo. It is very challenging to take macro photos of small, low-contrast spots against that background, at least without special lights. Here is a high-res crop from the original photo:

author: wraper
author_rank: Unknown
timestamp: July 24, 2016, 05:46:30 pm
content: Yep there is a life thrilling in your scope

author: saturation
author_rank: Super Contributor
timestamp: July 25, 2016, 06:22:13 pm
content: Concur, it does look like a fungus, and as you say then its between the outer protective plastic lens and the inner glass lens. If you disassemble the DSO [see Dave's teardown] you can fix this yourself.

author: wblock
author_rank: Regular Contributor
timestamp: July 26, 2016, 02:13:46 am
content: The problem with the lens fungus is that it can produce an acid that etches the glass. If this was a used piece of equipment, I still might be tempted to take apart the LCD and clean it. Found a scrap LCD panel today to see what it was like, but the plastic layer was actually glued to the glass.So... we'll see about an RMA. TEquipment contacted me today.

author: Fungus
author_rank: Super Contributor
timestamp: July 26, 2016, 08:57:33 am
content: Quote from: wraper on July 24, 2016, 05:46:30 pmI'm actually tempted to buy a GW-INstek. Is this a standard feature? Nobody mentioned it before.

author: saturation
author_rank: Super Contributor
timestamp: July 26, 2016, 11:55:55 am
content: Yes, if its there for a "long" time; the best way to find out is wipe it off and examine the surface. Given its a new model its very unlikely to be etched. As you have an RMA keep us posted and good luck.Quote from: wblock on July 26, 2016, 02:13:46 am

author: wraper
author_rank: Unknown
timestamp: July 27, 2016, 07:25:13 am
content: Quote from: Fungus on July 26, 2016, 08:57:33 amNo