This LCD display has backlight on or not? (ebay dispute)
CuriousOne
Posts: 931
Hello.
Below is attached picture of LCD module. For me, it appears to have backlight on. In item description, seller does not states wherever this display has backlight at all. He only says "green background, black letters". Actual device has no backlight at all.
So, does this image appears misleading for you?
Below is attached picture of LCD module. For me, it appears to have backlight on. In item description, seller does not states wherever this display has backlight at all. He only says "green background, black letters". Actual device has no backlight at all.
So, does this image appears misleading for you?
515 x 420 - 37K
Comments
In any event, unless the seller specifically states that a display is backlit, it's best to assume that it is not.
-Phil
And regarding the pads on the left, tomorrow I can show you the picture of another led module, with these pads exposed and nothing soldered to them, but it still has backlight.
All the LCDs look the same, but the packages and the product coding on the LCD without blacklight mention none in a translation of that rather obscure numbering code. You might Google some of the odd ball product coding that is printed on either the front or back of the board to determine what you were supposed to have.
The photo shows both sets of wiring for backlighting, so you can test it.
Trying to get vendors to change their style of business can be rather absurd. I once lived near a restaurant called Nasty Nora's, and Nora was indeed nasty. Once customer complained that a hamburger was too raw and ask for it to be cooked more, Nasty Nora handed him a refund and told him to get out. One another occasion I wanted to fill a thermos for work with coffee and was willing to pay for her to top it up at a price for so many cups without free refills. In her infinite wisdom, she said no, the coffee was their for paying customers.
She may have been dumber than a door post and on a hair trigger, but I suspect she is still in business.
Why extra pads, but no functioning backlight?
I just presumed that the manufacturers try to make all their products backlit, and the ones that fail are sold without backlit.
Very often the backlit is powered by the two pins 15 and 16, as the original 14 pin interface was sold for no backlit. But since the backlit is an independent circuit that requires substantially more power, another interface with larger pads would often be present to provide an independent power to the backlit... besides, backlights may not have the same voltage requirements as the LCDs logic.. often higher.
I generally onlly buy LCDs that provide a full document sheet with the devices. Why, some have the polarity of ground and positive that are reverse of what Parallax sells.. and I have burned up one finding that out.
1. Cheapest one - single led sticking into reflective pad from the one side under the display. Some have another led too, on opposite side. Very uneven illumination, but these often come with RGB led, so you have choice of backlight color.
2. Medium one - backlight is provided by tiny leds, which are placed in light diffuser under the display. Very nice and even illumination. But for high brightness, consumption can be up to 80ma from 5 volts, which is often way too much for portable unit.
3. Rarest and most expensive (I think so) one. These use EL pad for backlight, have very pleasant, cyan or emerald green backlight. To be honest, I never seen such display for sale alone, I had pair of them salvaged from various factory made devices (cash register, access control system, temperature controller), but they were still standard pin/protocol lcd displays.
I just skip the vendors that cannot provide adequate information.
http://www.ebay.com/itm/380465172544?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
Sellers P/N: RDE-LM12118
Google bounces back to ebay or seller webpage, where are no info available.
If we look at PCB, we clearly see the P/N: JM162B
Which, according to manufacturers datasheet, do has backlight: http://www.kentec.net/pdf/lcd/JM162BSPEC.pdf
In case you're taking a vote. No, it doesn't appear misleading to me. It looks like a well lite photograph.
I personally think it would be good for the seller to mention it doesn't have a backlight but I also don't think he should be required to say what it doesn't have.
I don't see anything dishonest or misleading about his ebay page.
For $2.78, it seems a good value. Backlighting always increases the price, especially cool colors such as blue or red to more than $5.00USD.
They do at least provide the pin out for proper wiring, but not the electric characteristics of K and A.
The reference to an RDE-LM12118 is indeed a product code. I've seen this or something similar in retail shops in Taiwan. I'd have to dig a bit, but I may have a sheet that would tell if it is a backlit device, and what the power requiremens are. But it is a 50/50 chance I have something. There are tons of LCDs out there.
'Sorry, but I seriously don't think you have a case against the seller.
-Phil
The PINS 15 and 16 for backlighting are rate at 4.2 volts and 120 ma, while the rest of the unit uses 5Vdc at 25ma load.
I also have an OKAYA document (Product #RG 12232-a) and it too has backlighting at 4.2 volts and 120 ma with the other power between 2.7 and 5.5 volts. A is + and K is -
The main reason I looked these up is that I feared the backlight voltage would be designated at less than 5VDC, and I am right. From a +5V source, you might have to insert a rectifier diode to get a drop to 4.2 volts or less.
Requiring the subject to be very close to be in focus is typical of a loupe, which is how it's listed. However, the photo of the lady wearing one and appearing to concentrate on something further way is a bit deceptive. Still, though, a loupe is a loupe, not a surgical telescope.
-Phil
Buyer beware. I use a 20x magnifier to examine for solder bridges on circuit boards and it certainly needs to be that close. Seems reasonable to me. What you need is a telescope.
and it do mentions backlight.
-Phil
This is an excellent data sheet.. the kind I look for with LCD purchases. But it is for a product line with various colors of backlight, and maybe includes the pulls with no backlight. There are even two types of backlighting STN, and TN, Position negative.
Of course, the JM162BSPEC doesn't tie into the RDE- ........... So it might not really be the PDF for your exact device, but that is the way things get done in Asia.. approximately.
They have a 99.28% approval rating and this is not a huge capital expenditure, so if you do have backlighting, great. If you don't, it is not worth returning.
Also, for LCDs that actually do include an LED backlight, the voltage rating will be the nominal forward voltage of the LED(s) (maybe more than one in series) at the rated current. The way to power such an LED is through a resistor from the 5V (or higher) supply. You definitely do not want to power any LED directly from a low-impedance supply.
-Phil
-Phil
If contacts aren't used, generally they are marked as NC (Not Connected) not A & K.
I have a lot of experience of buying electronic components in Asia without the benefit of documentation in English or Chinese. Or even when there is documention, it is obvious that the author doesn't comprehend electronics as deeply as a westerner. In other words, I have boxes and boxes of bits and pieces that were a purchasing mistake as I guessed wrong.
It is obvious to me that the vendor is in Asia with a less than perfect command of the English language. He may not have any idea of what you are trying to do as he simply wants to take orders and deliver product... customers in Asia don't generally suggest improvements in management or advertisement.
There might be another aspect as well. Probably the vendor bought 5 or 10 thousand of these units ten years ago when retailers were getting $25 USD apiece. But the market fell apart and now the seller is liquidating good new stock on EBay at near cost. So this vendor is selling these units at nearly no profit just to get back his capital and wants to be a good EBay vendor. He doesn't understand what you feel is missing from his ad as he have plenty of orders without complaint and he just wants to get his money out of the product. It is a clearance sale, not a bright new business that might be better through improved customer relations.
I've lived in Taiwan for nearly 20 years now, studied Chinese and Taiwanese all these years... and I still find that some things are just not done in western ways or communicated at the same level of detail that westerners expect. For me, it has been a source of profound amusement; for others, it causes culture shock and they feel that the Asians need to be taught the right way of doing things, the western way. I suspect it will never happen.
Plus, I have learned that buying on EBay requires me to notice all the details.. such as the fact that only 14 of the 16 pins are wired in the photo and that the documentation is for more than one model, both the backlit and those without.
If I were you, I'd just ask why you feel you have to make the vendor change his ad. Or that he has decieved you. He really hasn't and doesn't have to change. And you might never make him understand.
It really doesn't matter where or who I buy something, it the price of the unit is less that the cost of returning it to the vendor if I dislike it... I just accept the risk that I might get something that is a waste of money. At the price this is, it is hardly worth getting upset about being disappointed or having assumed something that wasn't.
http://www.dailymail.co.uk/news/article-2325471/Owner-destroys-276-000-Maserati-car-China-just-angry
In today's Taipei Times, there was a big photo of the owner of a brand new Maserati that was paying a group of men to smash the vehicle as he felt he had be decieved by the car's maker. Apparently the dealership he bought the car from in China had done a very poor job of after-market service, so the car has never run right. They were even using used parts that they acquired from unknown sources.
I sure the guy feels he is absolutely right... and rest of us are wondering what he is trying to achieve.
Of course, he didn't waste $2.78 USD, closer to a $500,000 USD.
There are much more shady ads than this on eBay.