Emerson LF501EMF4 Dead

[CraigR]

I'm out of ideas on this Emerson LED TV model LF501EMF It's totally dead no standby light or anything with button or remote.
First I thought it was the main board so I got one from ShopJimmy and get the same result so MUST be the power board. ShopJimmy did not have one so I got one off ebay and the same thing and I even put the original main back in and tried. I thought oh must of been a bad board I got from ebay so I told the guy and he sent out another one so I put that in and same thing (DEAD) I also put back in the Shop jimmy board and tried. So next I thought ribbon cables so I went through them checking for continuity and all checked out fine so I cleaned the contacts with an eraser and put back in. Still no go. All I can think of is that the shopjimmy board and my original main are bad but???
Any Ideas????

[ReeceyBurger123]

Re: Emerson LF501EMF4 Dead

Right ok as you know how to check for resistance check all the output diodes and fets on the power supply very common fault on these sets.

[CraigR]

Re: Emerson LF501EMF4 Dead

What are the chances of all 3 boards being bad?

[ReeceyBurger123]

Re: Emerson LF501EMF4 Dead

Very little this is why you need to spend time diagnosing faults rather than throwing boards at a tv. Check the psu for S/C first.

[CraigR]

Re: Emerson LF501EMF4 Dead

Checked all that on the original psu that's why I threw a main board at it. LOL Thanks for the input ReeceyBurger123

[nicholas1110]

Re: Emerson LF501EMF4 Dead

I had one of these recently with a bad panel. It was also showing a dead symptom. I powered the tv on with the ribbon to the panel unplugged and I got backlight. Plugged it back in and it was dead. Removed the trim and found a very badly burnt adress chip on one of the panel ribbons. So if suggest trying to power on with the panel ribbon disconnected from the main board.

[CraigR]

Re: Emerson LF501EMF4 Dead

Ok, just tried it with both main boards and the panel ribbon cable disconnected and still no standby light or any backlight. Could that little IR sensor board cause the whole TV not to work? If so any way to bypass and test?

[CapLeaker]

Re: Emerson LF501EMF4 Dead

what did you check on the PSU? Did you verify the PSU is dead?

[CraigR]

Re: Emerson LF501EMF4 Dead

on the original psu checked fuses diodes resistors and mosfets.

[CapLeaker]

Re: Emerson LF501EMF4 Dead

did you check if there is any voltage coming out on any of the pins where the ribbon cable plugs in?

[CraigR]

Re: Emerson LF501EMF4 Dead

Yes there was voltage with all 3 boards. I can get all of them if you think it might help.

[CapLeaker]

Re: Emerson LF501EMF4 Dead

what happens if you disconnect the t-con from the main board and turn the tv on?

[CraigR]

Re: Emerson LF501EMF4 Dead

Nothing like in post 6,7

[CapLeaker]

Re: Emerson LF501EMF4 Dead

That small ribbon cable on the bottom of the main board goes to the keypad and IR board? Does this cable split and run into 2 boards or is the key pad and IR on the same board?
Problem is that you can't disconnect that small ribbon cable on the main board, because you wouldn't be able to turn the tv on.

[CraigR]

Re: Emerson LF501EMF4 Dead

keypad is seperate and connects with 2 wires. I checked it and keypad is working for on/off

[paulstef]

Re: Emerson LF501EMF4 Dead

1. Near the ribbon cable connector, are there any voltages or pin descriptions? Or on the mainboard?
Can you post a picture of that side? We need to identify voltages and signals on that cable.

2. Do you have voltage on the LED connector?

[CapLeaker]

Re: Emerson LF501EMF4 Dead

then give it a try to disconnect the IR and turn on the TV.
Those Vestels are so cheap a$$ made, they don't bother anymore printing much on the board for pin out. lol.

[CraigR]

Re: Emerson LF501EMF4 Dead

Maybe I did not say it right but the button pad goes to the IR then the ribbon cable goes from the IR to main so I can't take out the IR.

[CapLeaker]

Re: Emerson LF501EMF4 Dead

The only thing that comes to my mind now is to trace everything from the IR boars to the end of the ribbon cable and put something non conductive tape over that part of the ribbon cable.

[CraigR]

Re: Emerson LF501EMF4 Dead

I am at a loss here. I thought I was luck because I got in another tv of the same thing. Long story short the IR board was bad and whatever combination of boards I use the best I can get it the standby light blinking slow but constant. Sent main back to shopjimmy asking for a replacement so if that does not work i'm junking it.