Element ELEFS552 Main Board Issue

[brucetv]

We found this Element ELEFS552 Tv at our cell phone repair shop door with the "donation" letter. We plugged it in and no picture, no sound, and no backlights, no power light. We opened it up and found a burnt regulator possibly. It has a WP 9H marking and has 3 prongs. The power supply looked clean and voltages are as follows
plugged in off plugged in on
5vSB 5.17DC 5.17
STB 0 v 0
GND 0 0
GND 0 0
+5 0.004 0.002
+5 0.003 0.009
12v 0 0
I will include some close up shots of the burnt circuit which cleaned up good so I might be able to solder a new one in if anybody can identify it. I couldn't find a schematic for the Tv. I'm following the traces on the main and the circuitry is close to the backlight plug so I'm wondering if there might be a possible short in the backlights that shut everything down. I also see CON 2 with GND/ADJ/BK and CON 3&4 going to backlights but I don't know how to test that. And a 4 wire connector with going to the main. Where do I start on this one? Thank you.

[Electronic Handyman]

Re: Element ELEFS552 Main Board Issue

I looked up that make model and it's a led tv that many ppl have had issues with , some ppl hate that model and a few ppl praise it in their reviews.
This is just my opinion but from all my yrs of doing repairs I've not really run into circuits frying like that unless a dead short has occurred.I'am really wondering if some kind of liquid had managed to find its way into that set.It's not uncommon for people to either spill water into a set or they tried to clean the screen and managed to get water into the set.It's also very common for the water to rot or corrode out the panels ribbons.I'd strongly suggest that you take a good look at the ribbons and their connections.Plus take a a good look at the leds. Again for any circuit to fry like that it has to be a dead short or maybe a really over loaded circuit and I doubt bad leds could fry a circuit like that.I'd also want to check the led circuit's wiring with a ohms meter see if you get any resistance or just a dead short .

[brucetv]

Re: Element ELEFS552 Main Board Issue

Thanks EH. I looked for any corrosion and didn't see any. In fact the inside was very clean and other than the crispy 3 prong circuit near the inverter plug it all looked good including the ribbons and board running horizontally under the panel. The main board is very basic for a 55" Tv and but it would have made a nice tv for the shop but I agree that it might be a bad investment to get a new PS and solder a new circuit in the main only to fry it again and have a BL issue or short in the panel. Off to the shelf for now and appreciate any advice as usual.

[brucetv]

Re: Element ELEFS552 Main Board Issue

I see shopjimmy has a 3 board repair kit for $55 for this Tv but I'm worried about a short in the panel or in the led strips that can cause damage to my new boards. Is there a way to test for this before install?

[budm]

Re: Element ELEFS552 Main Board Issue

You can test the power supply-LED driver board by itself by disconnecting the cable between the main board and the power supply board first, the use 1K resistor between STB pin and 5VSB pin, and then use another resistor between BK pin and the 5VSB pin on the power supply board, this should force on the power supply and the Backlights circuits, If the backlights still do not come on then you will need another 1K resistor between ADJ pin and the 5VSB pin.