Hi all!
So I have an Emerson 39" tv with a model number of: LC391EM3. The problem is the screen will not come on and once plugged in, there is a constant high pitched whine coming from the power board. The area it is coming from is circled in the attached photo.
Once you unplug the flex going to the main board from the power board the whining stops. I am leaning towards a bad PSU board that is not putting enough power out for the main board, but then again I thought I would ask for some input on this as well.
- Jeff...
ECU_Techie
Member
Last Activity: 11-02-2016, 08:26 AM
Joined: 07-16-2016
Location: North Carolina
-
Emerson LC391EM3 - Constant High Pitch Sound
-
Re: LG 55LS4500-UD: Not Staying On
[B]** UPDATE **[/B]
Ok, well this is a success story. Main board replacement came in the mail today and it fixed the issue. TV is on currently and working great! Thank you guys for your input and help on this and I thought it would be nice to provide a resolution to this issue.
Re: LG 55LS4500-UD: Not Staying On
[B]** UPDATE **[/B]
Ok, well this is a success story. Main board replacement came in the mail today and it fixed the issue. TV is on currently and working great! Thank you guys for your input -
Re: TV Board Schematics
Thank you Budm!Leave a comment:
-
TV Board Schematics
Hi,
I was curious, does anyone know where some good sources are for tv board schematics? -
Re: Insignia NS-50L240A13 - Not Turning On
Thank you both for the help on this tv. I also believe it is the main board as the IR board with indicator light also seems to have an issue. I did a quick test on the T-Con board connector pins and most of them don't read a voltage except for like one or two of them.
I believe at this point I will take my chances and mail the main board in to PTS Electronics and see if they can fix it. Once I hear back from them or get the board back, I will provide an update to where this tv stands. Once again, thank you both!Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
Ah, I gotcha this time. Ok, I took the BON pin out of the PS board end of the cable connector and plugged everything back up to the main board. I plugged the tv in and then jumped a resistor between the 5Vsb pin and the now empty BON spot on the connector.
The back-light came on now with the cable connected on both ends, but still no picture. Just the back-light staying on constant. Thanks for that good piece of troubleshooting advice guys.Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
No dice. Still no picture or back-light when the main board is connected to the PS board.Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
It has to be the main board. If I unplug everything from the main board and plug the tv in with the resistors in the pin outs of the one cable, the back-light comes on. If I only have the power cable to the main board plugged in, the back-light will not come on until I unplug the power cable from the main board. At that point the back-light comes back on.
I got the back-light to stay on by putting in a third resistor going between 5Vsb and PWM. In the picture below, you can see the three resistors and through the holes of...Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
An update, I took two resistors and jumped the pins of 5Vsb and BON and then 5Vsb and PON and the backlight lit for a second and went back off. I left the resistors on the pins and tested the voltage at the BON pin and with the resistors on the respective pins still, BON reads 5.15V. Also, two of the pin outs on the cable going from the PS to the back-light behind the panel read around 5V.
So does this point to a more then likely issue with the main board? I was trying to source another main board, and everywhere is out of...Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
Does anyone know what the proper voltage to the LED indicator light is on TV's? I measured the voltage right to a leg of the LED itself and it is reading 0.09V.
I just finished reading over Budm's LCD troubleshooting PDF which was informative. Thank you for creating that sir. You mentioned that if the 5Vsb pin out was showing voltage that the indicator light should always be on. Any idea why this might not be the case?Leave a comment:
-
Re: Insignia NS-50L240A13 - Not Turning On
Yep, that makes sense! There is no picture on the screen when I hold a flash light to it. Like I said, not even the red LED comes on down in the front corner. Unconnecting the cable going to the main board from the PS board did not bring a back-light either.
There is a cable running from the PS board to the left side of the screen. I assume that is the cable which powers the back-light? It is reading 0V down the entire connector. I don't have any 1K resistors so wasn't able to try and jump it.Leave a comment:
-
Insignia NS-50L240A13 - Not Turning On
Hi all,
I have a 50" Insignia LCD TV that will not power on or show signs of life. The gentleman I got the TV from said it one day would not turn on and would not even get the red standby light in the front corner anymore.
I opened it up and tested the PS fuse, it has 120V running through it. Testing the pin outs on the cable connecting the PS board to the main board I get the following voltages:
[LIST][*]12V - 11.94V[*]12V - 11.94V[*]GND[*]GND[*]12V - 11.83V[*]12V - 11.83V[*]GND[*]GND[*]PON - 2.93[*]5V1 - 5.14V[*]5Vsb - 5.14V[*]PWM - 3.32V[*]BON - Fluctuates... -
Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
Ok, well this TV is done for. Two things I believe are going on with it. I took off the panel to check the LEDs and see if they came on at all and while I had the panel off I decided to check from the backside to see if everything was good. No such luck...
I discovered the panel is cracked in two corners. I can assure you it wasn't from me taking it apart either. Apparently I was failed to be told the screen got cracked. At least it was a free TV!
I checked the LEDs anyways though since I got that...Leave a comment:
-
Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
For the voltages on the connector (CNL802), going to LED strip I only get a reading of 212V on the two D+ pin outs. The rest read 0V.
On the PS board though, it says CNL802 should read 135V. Is it saying it should read 135V on each D+ pin out instead of the 212V on each I am getting?...Last edited by ECU_Techie; 07-29-2016, 02:29 PM.Leave a comment:
-
Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
Yes, I do get an extremely faint image on one side of the screen and in that image there can be some parts that has horizontal lines/sections of it missing.Leave a comment:
-
Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
Ok, now armed with this new found outlook on the issue, this is the voltages for the pin outs starting in the left top column going down:
*Note: These readings were taken with the TV turned on and out of standby.*
[LIST][*] PWM_DIM - 1.03V[*] B13V - 13V[*] BLU_On/Off - 4.8V[*] GND[*] GND[*] A5V - 5.28V[*] Power On/Off - 3.36V[*] B13V - 13V[*] B13V - 13V[*] Vamp - 13V[*] Vamp - 13V[*] GND[*] B5V - 5.26V[*] B5V - 5.26V[/LIST]- Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
Ok, now armed with this
Leave a comment:
- Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
-
Re: Samsung UN39FH5000FXZA - No Picture, Has Sound
My DMM is set to 20V DC and that is what the pins all read from the top down.
**EDIT**
Ah, my bad. How blind of me. It didn't dawn on me that it is two rows of pins. I was thinking the first column was the name of the pin out and the second was the value for some odd reason... I really need to sleep more!! Haha!...Last edited by ECU_Techie; 07-29-2016, 01:53 PM.Leave a comment:
-
Samsung UN39FH5000FXZA - No Picture, Has Sound
Hi guys,
Ok, so I just picked up this TV which, at first glance looks like it has no picture, but upon unconnecting one of the two cables providing display to the screen, you can tell the back-light for one side of the screen lights up.
I checked all the voltages on connector CNM803 on the PS board and they all checked out good for what they should read according to the board. They are listed below:
[LIST=1][*]PWM_DIM - 13V[*]B13V - 13V[*]BLU_ON/OFF - 13V[*]GND[*]GND[*]A5V - 5.2V[*]POWER ON/OFF - 5.2V[/LIST]
I then checked the surface mounted... -
Re: Multimeter Settings!
What would be some recommended ESR and cap leakage DMM you guys use?Leave a comment:
-
Re: Samsung PN51D530A3F - Has Sound, No Picture
Ok, so I went back to test the Y-Sus board and started with the main power board instead. I actually noticed something I don't think I realized before, the VA test point reads the correct value of 57V on the sticker, but when I go to test the VS point, it will read around 199V for a second and go back to reading just the starting value of 1. The sticker says VS is 207V. This is with the power connector to the Y-Sus board disconnected. As expected, when I test the two VS pins going to the Y-Sus board, I get the same reading. Something...Leave a comment:
No activity results to display
Leave a comment: