Emerson ELEFS552 Tv Main problem

[brucetv]

We found this tv at our front door with another "donation" letter. We are a cell phone repair shop but we get bored sometimes and always eager to learn new troubleshooting on other gadgets. The Tv had no power light, no power, no backlights, and no sound. Power supply voltages were:
pwr off pwr on
5vSB 5.17 5.17
STB 0 0
GND 0 0
GND 0 0
+5 0.004 0.002
+5 0.003 0.009
12v 0 0

[brucetv]

Re: Emerson ELEFS552 Tv Main problem

We found a burnt circuit on the main but I can't tell what it is so I will include pictures. We found a 3 board repair kit on shopjimmy for $55 but I'm worried about a panel or led short causing this. Here are the pics and is it safe to put in the new boards? The burnt device(looks like a regulator) has WP 9H markings and is to the right of the red inverter cable. It has 3 pins

[CapLeaker]

Re: Emerson ELEFS552 Tv Main problem

First thing, I think that this is an Element not an Emerson.
Look at how things are hooked together. What was hooked up to that red connector (I think it sez inverter?)? What ever goes there is the suspect.

To check the PSU, disconnect the main board, leave the backlights connected and force it on with a 1k resistor between STBY and PSon, then another between STBY and BLon.

[brucetv]

Re: Emerson ELEFS552 Tv Main problem

Yes sir, your right, it is a Element. We had a Emerson sitting next to it and I got the two mixed up. I have the resistors but on my PS I have
5VSB
STB
GND
GND
+5
+5
GND
GND
12v
12v
On the top right I have red and white wires that look like they go to the backlights that have CON3 and CON4. The connector that plugs into the main where that burnt circuit is plugged into that connector next to the PS to Main just to the right marked GND ADJ BK but it only utilizes two wires into a 4 plug connector and goes the ADJ and BK only according to the connector. So in my case where do I put the resistor jumpers on my PS? Thank you so much for the help.

[CapLeaker]

Re: Emerson ELEFS552 Tv Main problem

a 1k resistor between 5VSB and STB turns the PSU on. To force on the backlight, a 1k resistor between 5VSB and BK is needed, you also may have to do the same thing to ADJ.

[brucetv]

Re: Emerson ELEFS552 Tv Main problem

Okay, we were successful forcing the backlights on and they work great. No dark spots so now I can rest easier knowing I don't have a short in the backlights that could have caused that WP 96 to melt next to that red inverter connector on the main. I didn't want to damage the new main so thanks for the tip so we can start the process of elimination. We also got our 3 board kit in today and the Tv fired right up. We used a thermal scope on that WP96 and didn't see any temperature spike in case we had to pull the plug real quick. The picture is Black Friday quality and the speakers really suck but we now have a 55" Tv for our waiting area for a $63 investment. I pulled the caps on the PS and tested them on my ESR 70 and they all checked out fine. Something allowed too much voltage into that red inverter connector on the main or a dead short somewhere. Oh well, we now know how to force the backlights on a Tv and I thank you sir for the valuable knowledge we all learned in my shop today.

[budm]

Re: Emerson ELEFS552 Tv Main problem

Glad to hear. You should also go to the on screen setup to turn down the backlights level (not the brightness) as low as you can to extend the life of the backlights.
Same board as in this thread too?
https://www.badcaps.net/forum/showth...576#post652576

[CapLeaker]

Re: Emerson ELEFS552 Tv Main problem

Okay, we were successful forcing the backlights on and they work great. No dark spots so now I can rest easier knowing I don't have a short in the backlights that could have caused that WP 96 to melt next to that red inverter connector on the main. I didn't want to damage the new main so thanks for the tip so we can start the process of elimination. We also got our 3 board kit in today and the Tv fired right up. We used a thermal scope on that WP96 and didn't see any temperature spike in case we had to pull the plug real quick. The picture is Black Friday quality and the speakers really suck but we now have a 55" Tv for our waiting area for a $63 investment. I pulled the caps on the PS and tested them on my ESR 70 and they all checked out fine. Something allowed too much voltage into that red inverter connector on the main or a dead short somewhere. Oh well, we now know how to force the backlights on a Tv and I thank you sir for the valuable knowledge we all learned in my shop today.

perfect! YW