EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: mcinque on July 29, 2013, 10:14:11 pm
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Hi,
I've got a question for you about this brand new Rigol DG1022 that I've bought from a Rigol authorized reseller.
The instrument works well and is really worth the money, but its display shows some strange symptoms:
- at the boot, before the logo and the backlight, the lcd shows strange perpendicular lines (see photo compared with a DM3058 booting up that shows nothing)
- when the brightness/contrast are set too high or low, the lcd shows that lines on the background (see photo)
Compared to my DM3058, the DG1022 (that - I bet - use the same kind of lcd) seems to have a "not so good" display, that shows minor defects in particular conditions.
Of course if I set properly the brigtness and contrast, the screen is clear and readable and I have no lines visible, but the DMM don't have this kind of behavior.
My provider sent me a video testing another identical unit he have in stock. Result: almost same results, but with different pattern.
At the european service center in Germany, an engineer said that also his unit shows that symptoms :palm:.
I'm waiting a reply from Beijing, their support has been always kindle and technically well prepared, but I'm thinking that a big batch of defective displays has been used.
What do you think about it? It's an hardware trouble or a engineering mistake? And your DG1022, has the same symptoms?
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I got an DG1022 about half year ago from Batronix, and it shows a similar thing. I don' t think it is a defect, but just a un-initialised graphics display that needs time to settle. Once it is booted with the logo etc... it works OK.
They probably all have this.
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The DM3068 has a LCD test in the service guide, maybe the DG1022 has the same.
If the visual test ok then I think it's OK.
for DM3068
Inspection method:
Press and hold the second menu key on the left of the front panel and turn on the meter, after about 5 seconds and until you hear a switch sound of relay, the meter starts testing the screen and a message “Press ·Help· Key to Switch, Hold ·Help· Key to Exit” is shown on the screen.
- If you press Help, the screen switches between Full white (all pixels go on) and Full black (all pixels go out). Observe the luminance fluctuation of the LCD and inspect if there is any light spot or dark spot.
- If you press and hold Help for about 2 seconds, the display returns to normal measurement state.
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My DG1022 shows identical behavior. Not really anything to worry about I think, display shows normal behavior once powered on...
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If I shut mine down and restart it rather quickly it will show some yellow horizontal lines as it boots. It's always done this though since
new. I initially thought it may be a problem and requested the latest firmware, but even after updating it made no difference so I
just assumed it was nothing to get concerned over. As otherwise the instrument works fine.
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Thank you for your replies. I've understood that "it's a feature, not an error" :)
I was the quality manager at Rigol, I would never have allowed that a product with those symptoms were being launched on the market, even if they are stupid graphic initialization patterns. The perception of quality decreases dramatically imho.
It would have been better (and simple) to delay the power delivered to the lcd by one second, to make it turn on after the initialization, just in time to show the company logo.
Thank you again for your hopinions.
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Probably caused by not following the LCD initialisation seqence properly - ideally you power up the logic before applying the LCD drive voltage, but it's common to just use the same supply with no sequencing.
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I was the quality manager at Rigol, I would never have allowed that a product with those symptoms were being launched on the market, even if they are stupid graphic initialization patterns. The perception of quality decreases dramatically imho.
The basic design of these generators is around seven years old, when Rigol did the now obsolete DG2000 series. The DG1000 budget series was derived from the DG2000 series by removing features. I doubt they had someone caring about product quality at that time. Maybe they still don't, at least not when it comes to software.
Anyhow, Rigol just milks that particular design as long as people buy. And those who don't want it can get the newer generators like the DG4000 series. This is where Rigol puts in some development effort (except in their PC software ...).
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ideally you power up the logic before applying the LCD drive voltage
:-+ exactly!
The basic design of these generators is around seven years old, when Rigol did the now obsolete DG2000 series.
I understand now because the DM3058 (wich is most recent) doesn't have that issue. They have revised the intialization sequence.
(except in their PC software ...)
I definitely agree.
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Hello! ;)
I introduce myself first. I graduated in Electrotechnical Engineering and electronics hobbyist.
I have a Waveform Generator Rigol DG1022 for over two years and recently came the following problem:
Orange spot in the center of the LCD display, looks like a leak.
The spot increases day by day
Someone witnessed similar problem? LCD defect?
Attached photo:
Thank you
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I was the quality manager at Rigol...
Really? When was that?
Perhaps you meant "IF I was"?
The perception of quality decreases dramatically imho.
That applies to forum postings, as well. ;)
[Don't take offense. I'm just pulling your leg.]
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I was the quality manager at Rigol...
Really? When was that?
Perhaps you meant "IF I was"?
ahem... yes! oops! bhwhhaah :-DD damn maccaroni keyboard mode! ^-^
The perception of quality decreases dramatically imho.
That applies to forum postings, as well. ;)
lol ;D
[Don't take offense. I'm just pulling your leg.]
Don't worry, I appreciate your humor:)
Hello! ;)
Orange spot in the center of the LCD display, looks like a leak.
mmm... I would open that FGEN and take a look what's happening inside. Are you sure that the spot is inside the lcd or there is a possibility that is between the lcd and the protective glass? Maybe mould?
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Why worry about a few stray lines that appear on the LCD at boot time? They have zero impact on the usability of the item.
I have a DG1022, noticed the same thing when I first powered it up, but thought no more about it. :=\
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Hi mcinque
The spot is not in protective glass, is in the LCD and is increasing.
I do not open the DG1022 because I'm waiting reply from Rigol (if open the warranty void - I think it was 3 years in Europe).
Here's one picture with more detail.
Thank you
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The spot is not in protective glass, is in the LCD and is increasing.
I've never seen that kind of issue (however I've not seen many LCD issues, so I'm not an expert) but it seems really something that is leaking inside...
Why worry about a few stray lines that appear on the LCD at boot time? They have zero impact on the usability of the item.
I have a DG1022, noticed the same thing when I first powered it up, but thought no more about it. :=\
Well, I've got a DM3058 before that FGEN, ant that has no pattern at boot. So my first thought was that lines could be an issue or a defective unit.
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By the way, my unit on the boot also show 4 or 5 thin horizontal lines but nothing really important.
RIGOL already responded and said that the cost of repair are 300€ (the warranty time are not 3 year? :-//)
The spot of my unit seems to be leaking fluid from the LCD
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Absolutely, 3 Years warranty in EU as they states:
"The mainframes of RIGOL’ s products have a three-year warranty and the accessories such as probe and test pen (with the exception of power cord, USB and BNC cable) have a one-year warranty .
http://www.eu.rigolna.com/warranty/ (http://www.eu.rigolna.com/warranty/)
edit: it is funny that they ask for repair more than the cost of the product.
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Hi mcinque.
I'm not sure if I can activate the warranty. I bought on the internet in Door2doorshop.com. Maybe can I open, now, the device at my own risk. I think it is hard to find an LCD on the market. No longer trust in Rigol
Thanks for the support.
Here's a comparison photo
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I'm not sure if I can activate the warranty. I bought on the internet in Door2doorshop.com.
Why not? You've surely an invoice of that purchase.
I think it is hard to find an LCD on the market.
Well, it's not easy to find the exact model. But it's a dot matrix display, if you identify the driver chip you're a step ahead.
No longer trust in Rigol
Try to assert your rights and see what happens. The worst case you could get is a "no warranty".
Here's a comparison photo
It seems strange to me however that it's a leakage. Even if I'm not experienced in that kind of faults I guess that in a LCD display, if some liquid is coming out, you should see some differences in the graphic (at least some variations caused by the missing liquid), don't you agree?
That spot covers completely the graphic and is not translucent. It seems really something that is in between the lcd and the screen. Could you please take a shot when the FGEN is off, lighting up the screen with a flashlight?
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I keep all my test gear plugged into a long power strip which I turn off when I'm not in the lab. Saves a bit of power and gives me some confidence that I haven't left something on to short out or whatever while I'm not there.
Anyway, my DG1022A makes a rather disconcerting click whenever its input power is turned on. Actually, it's about three clicks, and sounds a lot to me like a relay closing, powering up something, then opening again to a standby mode. During that period the display flashes and makes some funny lines. This behavior actually bothers me more than a bit of noise on the display when I actually turn the device on.
I don't know why these companies so hate real power buttons. Can it be cheaper to have a softkey, standby power circuit, relay etc, then just having a latching power switch?
It's probably worth stating that the unit works just fine, so maybe I shouldn't judge the engineering.
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I don't know why these companies so hate real power buttons. Can it be cheaper to have a softkey, standby power circuit, relay etc, then just having a latching power switch?
Because then they have to either deal with mains near the front panel (and LV stuff), or design it with a push rod to activate a rear mounted mains switch from the front panel.
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The reason these LCDs look so poor is they are passive-matrix STN LCDs. You've been spoiled by TFT LCDs. These drive the rows and columns directly. Any leakage or imperfections in a single pixel will lead to more or less line bias allowing more leakage to occur creating the effect of lines. Quite often you can see where the lines meet at a single pixel by the intersection, though it is not always visible. TFT LCDs get around it because no one pixel can affect more than itself, and also the manufacturing requirements are generally more strict. TFT-shorted panels just don't work at all.
The Agilent 33220A (DDS) uses an STN LCD much the same as the Rigol although it has a stronger blue tint. It has the same line bleed issue and will flash lines for a few frames when turned on.
For comparison, the original Tek TDS100 series used a black and white 320x240(?) pixel STN LCD and looked terrible (line bleed was a huge issue); when it was released colour TFT LCDs in that form factor were fairly new, so it's understandable.
It always annoyed me the DS1000E did that screen flicker on power up. The odd thing is, they had a backlight enable line on the power board. It's used for the screen saver mode, which can blank the screen after 4 hours or so... They could have turned off the backlight during that initial flickering so you don't see it. The DS1074Z do this, you can see a few lines on the screen before the backlight fires up, that's fine.
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Hello guys. Hi mcinq.
Here's a picture with FGEN off and lighting up with a flashlight (taken in a angle of 45 degrees) the orange spot is visible.
In another picture IMG_0466a (at starting) is also visible a white spot under the orange spot. The white spot desappears after startup.
Concerning the warranty the dealer (Door2doorshop) did n’t answered my email. I’m still waiting.
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Hello guys. Hi mcinq.
Here's a picture with FGEN off and lighting up with a flashlight (taken in a angle of 45 degrees) the orange spot is visible.
In another picture IMG_0466a (at starting) is also visible a white spot under the orange spot. The white spot desappears after startup.
Concerning the warranty the dealer (Door2doorshop) did n’t answered my email. I’m still waiting.
I have open few similar LCD (from another test equipment)
Its non repairable, looks like some fungus/bacteria is develop inside the LCD, probably enter during LCD manufacturing...
spoiler... its will getting larger and larger... it's alive !!
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Agree, like I said initially
Maybe mould?
that's probably some kind of mould or fungus... how much relative humidity do you have in your lab?
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These drive the rows and columns directly. Any leakage or imperfections in a single pixel will lead to more or less line bias allowing more leakage to occur creating the effect of lines.
Thank you! Now I understand. +1 :-+
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Agree, like I said initially
Maybe mould?
that's probably some kind of mould or fungus... how much relative humidity do you have in your lab?
60-90% ( i'm live in tropical country )..
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mmm... maybe the high RH has helped that symptom.
I see that door2door is a China based company. Why are you claiming EU warranty while the seller is Chinese? I guess that an EU warranty is only for purchases made in EU, am I wrong?
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Agree, like I said initially
Maybe mould?
that's probably some kind of mould or fungus... how much relative humidity do you have in your lab?
In the Winter the RH on my lab is around 60% when across to 70% I switch on the dehumidifier.
There will be no way to stop the progression of the mold?
I still waiting for Door2doorshop reply
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There will be no way to stop the progression of the mold?
If it is outside of the LCD you could just clean it.
If it is inside then that LCD is no more. It is pining for the fjords. It is an EX-LCD.