Re: Need help hooking up LED back light strips.
Hi mikey5791,
thanks for your interest. The first batch of strips came broken due to poor packaging. Now I have just received the 2nd batch of strips, they seems to be ok but I have not tested them as yet. As we are fasting these days so I will test them some time after 2nd week of May.
I do not know the cause of the lines but I suspect an IC MAX9217 on TCon board getting hot. Could this is the culprit that is causing the lines I am not sure. This IC is expensive here about £13 and you get 5 ICs from China for a bit...
mzb
Member
Last Activity: 05-25-2021, 12:18 PM
Joined: 01-22-2021
Location: London
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Re: Need help hooking up LED back light strips.
I found out the problem I am having. As suggested by mikey5791 in his letter No.24, I tested the LED Strips with a 4.5v pack of batteries, and I got strange and wired results. in one strip if the first 3 LEDs tested no glow but the last LED on the strip would glow. If the first 2 LEDs tested, they wont light up, but the 3rd would. and so one, but you can not predict which one would glow.
Anyway I have ordered another set of strips, which I would receive some time in April.
I am also having problem with the display. I...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi R_J thanks for your letter, yes it is indeed DF6113. I just found out that one of the strip has short circuit, if I detach it the other one lights up more. Let me sort out the strips first then I will do what you wrote in your letter. I will come back to you.Leave a comment:
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Re: Need help hooking up LED back light strips.
Hello R_J, thanks for your comments. I am not at all very well versed in electronic, and you have seen the example of me shortening the IC. I would appreciate it very much if you could shed some light on why these boards are not delivering the required voltage to the strips to light them up. As I have mentioned in my previous letters that I am injecting about 20V but I am only getting 6.5 volts at the strips headers. I have tried both the boards from different suppliers, the result is the same. Have a look at the pics. I am attach...Leave a comment:
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Re: Need help hooking up LED back light strips.
Regarding your letter No.24, I am attaching photos of both the new and old boards. They are exactly the same, axept new one has a Cap. before the headers. As far as your suggestion of insolating the connection, I would do it when the whole setup start working. If you refer to my letter No.17, these strips start glowing at 7volts and fully at 9 volts. What I am getting is only 6.5 volts at the header when only one strip is attached and it drops to 6.3V when both the strips are attached. I did change the Vin at another place but the...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi mikey,
Yes I have reckecked all the vin, but I will resolder them again, just to satisfy myself.
The Dim and Start wires are soldered to the heads on Power board from where they go to the Logic Board. Have a look at the photo attached.
File Type: jpg 20210317_151311.jpg (64.5 KB, 4 views) which is attached to my previous letter.
When you press the Power On switch, there is a LED which glows properly as it has always done when the monitor was working. There is no sign of light at the led strip when it is switched...Leave a comment:
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Re: Need help hooking up LED back light strips.
1. The monitor was working perfectly. Then one day I had a red hue at the bottom left of the screen for few minutes it went way, after few days it became permanent. At the same time both the upper and lower half of the right side screen became dark.
After taking out LCD Bulb from the monitor I tried it outside and the upper tube was glowing half white and the bottom one was glowing half red.
There were no vertical or horizontal lines even after the above phenomena.
I tried the jumper modification after ordering...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi, I just received a new power board from Hongkong, tried it but the result is the same. Without load I am getting 18.6V but after connecting the strips the voltages drops to 6.5v and the result is Screen2. photo. I shortened the first board's voltage regulator (see photo), both strips glue properly and output with load is 8.6 is Screen 1. Either the strips are of the wrong wattage or input voltages should be more. The 18.6v is max. I can get from the power board.
The other problem I am facing is that I am getting all sorts...Leave a comment:
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Re: Need help hooking up LED back light strips.
"It's hard to tell from theses China sites. If it is this board for driving led's, it's output is only 9~10v?[/QUOTE]"
Hi R_J, I injected voltages from 6.5 to 9.5 volts. At 7v the strips started glowing and at 9.5v they were shining brightly. I think there is a problem with the board. Any way I have ordered another one.
Thanks for your help anyway.Re: Need help hooking up LED back light strips.
"It's hard to tell from theses China sites. If it is this board for driving led's, it'sLeave a comment:
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Re: Need help hooking up LED back light strips.
Hi R_J, thanks for your reply. I ordered the kit from "AliExpress ZBLED Bars Store". I am attaching the photo. The seller has refunded the money immediately so I am free to reorder the kit. But wondering would I get the right one this time.
Hi mikey, now that I have been refunded the money, I will certainly resolder the red and black wires to the strips. See what happens.
I do not know the electronic very much, but what baffles me is that I am getting the same voltage which are injected into the board and getting...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi mikey, thanks for your reply.
You said "If there are only two leds are shining bright instead of the whole led strip, i suspect the led strip is faulty." All the LEDs are working, except the 2 top LEDs which are shining brighter then the rest(see ONE) when both strips are connected. When only the strip which shining bright is connected, the 3rd LED also glow but not as bright(see THREE).
When both strips are connected, the brightness also differ slightly, say 100 and 80.
The input and the output voltages...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi, thanks for your reply. First "Have you tried to test run your monitor to see how bright", yes I did, and saw the only 2 LEDs which were shining bright at the end were illuminating that part of the screen, rest of the screen was not.
Then "There is a suggestion to solder the cable connector of positive(red) at the positive end of your led strip and the negative (black)", this is not clear to me. Do I have to resolder the Red and Black wires to the LED strips ? That means removing the heat shrink...Leave a comment:
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Re: Need help hooking up LED back light strips.
I just checked the LED Strips individually they light uniformly but not bright. I am tapping positive from Capacitor drawing 17.6 volts. I have checked my connection and soldering. They seems ok. I do not know what the problem is.Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi there, I am sorry to reply to you so late. I am having all sorts of problem installing the back lights. Although the new LEDs are getting about 18v but they are not as bright as it should be, and in one strip the last 2 led are brighter than the rest, but immediately after these there is one with faint glow and rest of them are glowing but not as bright as it should be.
Could it be the LEDs are not getting enough amps.Should I chose another point for voltage.
The another mistake I did not to record the sequence of...Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi, thank you for your support and reply. One last question, would it be beneficial to use Buck Converter to reduce 16.5Volts to regulated 12Volts or it does not matter.Leave a comment:
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Re: Need help hooking up LED back light strips.
Hi there, thank you very much for your encouraging reply. Unfortunately regarding VIN, DIM and GND nothing is printed on the board, but please have a look at the board, I have written various colors of wires and voltages in OFF/ON condition. You will also see all the voltages at different points on the Power Board. I would do as you suggested, but I want to know is, whether to disable inverter, or leave it as it is. If the inverter has to be disable, then how ?Leave a comment:
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Need help hooking up LED back light strips.
Hi all, I am new here and a novice.I have got the LED strips from china and I am ready to install.
I just want to hook this setup with your help. Please see the photos of POWER board and LED board.
Is it ok to connect the red cable from LED Board to the POWER board's DIODE
with 19V.
Is 19V ok or do I have to use STEP DOWN board to drop from 19 to 12V.
There are no marking on this POWER BOARD, so
I want to know where to connect those 2 yellow wire coming from LED board.
Presumable it should be connected to those YELLOW and WHITE points on the... -
Dell ST241B Monitor
Hi folks I am new to this forum, so please bear with me.
My monitor first became pinkish at the bottom half of the screen and then second day it became blank. If switch on with the same pinkish colour at the bottom left of the screen and the screen goes off exactly after 10 sec. I am enclosing the photos of the power panel with voltage reading and screen shots. These screen shots were taken using CCFL inverter. You will see the left of the screen is illuminated and right sides are dark. The 10sec. switch off to me indicate some caps are gone, but apparently they seems ok as you can see... -
Re: New Members - please post your introductions here
This forum is very funny. I just posted a message and I received a notice that I have already posted a message 5 min. ago.Leave a comment:
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Re: New Members - please post your introductions here
I am completely lost in this forum. I want to post a question and I get the message that I am not authorise to post. It is very frustrating.Leave a comment:
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