Re: LG 55LW5300 Backlights on, "Black Screen"
Thanks, I checked the power on flow chart and seemed to be getting voltage everywhere it wants me to check. Everything seemed normal.
I also tried to navigate to the cable channel to see if I have sound but I can't hear anything.
Also, is it normal for the main IC to get too hot to touch after about 30 seconds of powering on (touching the heat sink)?
Lastly, the TV started shutting off on its own after about 25 seconds of operating and turning back on. It wasn't doing...
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Re: LG 55LW5300 Backlights on, "Black Screen"
What's an SCA and how do I check it?
Also I'd like to correct something from my opening post. I didn't see there were a second row of pins on the main connector between the power board and main board. The power on pin reads 3.4v and the pin under it reads 24v. I checked all voltages on the second layer and they were all fine. No voltage on the error pin.Last edited by SmartSped; 05-07-2023, 02:38 PM.
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LG 55LW5300 Backlights on, "Black Screen"
Hello all, I was given an LG 55LW5300. When plugged in I get backlights but no picture. I checked voltages and found the Power On voltage to be 3.4V instead of 24v. All other voltages are normal at a powered on state. I did look around for solutions and found it could possibly be the IC's needing reflowed. I did this with my hot air rework station and this did not solve the issue. I'm not above replacing a board but I'd like to know which board it might be. Seems like a motherboard problem to me but I'm not 100% sure. Any ideas what the problem could be? Photos attached of boards and TV at On...Last edited by SmartSped; 05-07-2023, 11:01 AM.
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Re: VIZIO VA26LHDTV10T has white vizio logo before pressing power on. no backlight.
I know this is an old thread but I just wanted to touch on what Aaron said back on page 2. I checked all my voltages and checked all of the voltage regulators and everything looked good so I changed out the cap that Aaron referenced and it fixed the issue I was having which was a white standby light with no response from the power button. For reference sake, the cap in question is a 330uf 16v and is labeled C117. My tester said the value on the old cap was 347uf.
Thanks!
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
Put the 1K resistor on the A5V and BL-On pins and turned on the TV. It will still shut off (backlight included) after about 3 seconds. The only difference being that when it tries to turn on again, the green light turns on for a couple of seconds less and nothing shows up on the screen and then repeats this process.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
I checked the Ohms all the way from the inverter board to the DET_5v and I got very close to 0 Ohms. I even wiggled the cable around a little to make sure there wasn't a open circuit somewhere. I thought I had 1K resistor but it's one of the ones I don't have. I'm gonna order one and as soon as I get it in to test it, I'll report my findings. I have the BL-on wire pulled from the plug.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
I traced that error pin all the way to the main board where it leads into a couple of resistors right next to the plug. On the main board side of the power board, the pin is labeled DET_5v
Should I go ahead and try to force BL-on with a 1k resistor?Last edited by SmartSped; 03-02-2016, 08:28 PM.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
I'll be at work for most of the day but until then, I did take a couple of more photos including the bottom of the power board and pinout for the Inverter cable.
How would I tell if the error pin is being used or not by the inverter?
And yes, it does seem weird that everything seems normal except BL-on cycling on and off....Last edited by SmartSped; 03-02-2016, 08:02 AM.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
I see what brown spots you're talking about now. That's where I got messy from the flux and the light isn't shining on it. It looks a lot clearer than what it is in the pic. I'll do some more testing per your instructions and report back tomorrow.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
As I mentioned in the first post, I replaced ALL caps. All of them are correctly installed and have proper values. Some have higher voltage requirements but that's it. Before I replaced all the caps the TV was doing the exact same thing.
So just to be clear on the situation, without the inverter board installed:
PS-on and BL-on (from main board to power board) give me constant 2v and on/off cycling 3.3v respectively. I measured the 24v lines from the power board to the...Last edited by SmartSped; 03-01-2016, 08:01 PM.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
Yes it still cycles on/off. Ps-on and Bl-on maintain the same operation as before. Would it be possible that it may still do this because now it can't find the board?
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
Hey thanks for the response. I ran tests on the the PS-on and BL-on pins. The PS-On pin gets 2 volts through the whole process after I push the power button. The Bl-On gets 3.3 only when the backlight cycles on/off. One thing strange I noticed while doing this test was a low hissing/crackling noise coming from the bottom of the inverter board around the bottom transformer. Sounds kind of like a cat hissing. After the backlight cycles on, about a second later, the hiss slowly developed and then...Last edited by SmartSped; 02-29-2016, 07:17 PM.
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Re: Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inver
Ok finally. Here's some pics of the LCD....
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Samsung 320MP-3 Power cycles on and off (already replaced caps on power and inverter)
Hello,
I have a Samsung 320MP-3 (LH32HBPLBC/ZA) that the power keeps cycling on and off on. When I plug it in, the light turns green and what seems to be a perfect picture displays. After about 3 seconds, it shuts off and the standby light blinks about 3 times and then tries to turn back on again, repeating the process. I have already replaced the caps on the inverter board and power board and saw absolutely no change in the TV's functionality. Does anyone know what else could be wrong with this TV?
EDIT: I will upload photos when I can get the forum to stop logging...Last edited by SmartSped; 02-27-2016, 01:23 PM.
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Re: Emerson BLC320EM9 Blinking Green and shutting off
I finally got around to testing if anything was grounding out. I did not see any score marks on the power board. I looked for any damage on the transformers and didn't see any obvious signs of damage. I also tested to make sure the wires coming out from the transformers were not grounding out against the chassis.
I also tested the secondary portion of all the inverter transformers where the plugs are to the backlight and they all had similar Ohm readings. No shorts and no opens....Last edited by SmartSped; 12-07-2015, 05:47 PM.
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Emerson BLC320EM9 Blinking Green and shutting off
Hey guys. I have an Emerson BLC320EM9 and when I try to turn it on, it blinks for about 12-13 times and then the light goes back to red. Nothing is shown on the screen. The screen doesn't look damaged and the guy I'm repairing it for confirmed that as well. When I turn it on, I hear something charging up on the inverter board like a transformer or something and it does make a barely audible high pitched hum before shutting back off a few seconds later. I've searched out this problem and most seem to think it's something bad on the inverter board. I wanted to see if Shop Jimmy had a replacement...
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