Vizio E65-E3 Dead after backlight replacement

[budm]

Re: Vizio E65-E3 Dead after backlight replacement

Can I see the pictures of the whole backside of the TV showing how all the boards are connected together?

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

Pic

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

So I received the new set of LED's from Ebay and used a DMM to check for zeners. I am not going to say they don't have them, but I will say they are not detectable with a DMM. I make the statement not detectable with a DMM because I believe this being a fairly new set, some changes could have been incorporated for LED protection other than just a simple zener and there could be cases where the DMM voltage in diode check mode (2.5V to 3.5V) may not show the device.

And, I will be sending these back as they are not what I had ordered. I believe this being a 60 inch 4K TV it is worth a bit of investment to keep it going. I had reviewed ShopJimmy and he was selling an upgraded version LG Innotek Rev02 that claims not to deteriorate and emit blue only so soon. The Ebay seller had these listed for a reduced price, but it was not accurate as what I received appears to be original supply.

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

I ordered a used power supply from an e70-e3. The only difference i could tell is an extra cap and the jumper where it tells the model. I moved the jumper and desoldered one cap. It works for about five minutes then the leds turn off for about ten seconds and then come back on for a few more minutes before repeating this cycle. Any thoughts on why it would be doing this?

[alfatv]

Re: Vizio E65-E3 Dead after backlight replacement

I ordered a used power supply from an e70-e3. The only difference i could tell is an extra cap and the jumper where it tells the model. I moved the jumper and desoldered one cap. It works for about five minutes then the leds turn off for about ten seconds and then come back on for a few more minutes before repeating this cycle. Any thoughts on why it would be doing this?

Probably there are more differences. Since you have both boards, compare every single component side by side.
Another option is to use e70 board as reference to help you fix original one.

[budm]

Re: Vizio E65-E3 Dead after backlight replacement

I ordered a used power supply from an e70-e3. The only difference i could tell is an extra cap and the jumper where it tells the model. I moved the jumper and desoldered one cap. It works for about five minutes then the leds turn off for about ten seconds and then come back on for a few more minutes before repeating this cycle. Any thoughts on why it would be doing this?

Power supply for the 70 inch panel may have higher LED drive Voltage and current dues to more LEDs for larger panel, so it may be over driving your 60 inch LEDs.
And with the old power supply board, how does the backlights behave?

[R_J]

Re: Vizio E65-E3 Dead after backlight replacement

The extra cap is in the pfc circuit, which is different between the boards. The jumper does nothing, it is for indicating the model only
Re install the C1 capacitor, maybe it will stay working.

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

I reinstalled the cap and it still does the same.

[R_J]

Re: Vizio E65-E3 Dead after backlight replacement

.

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

So I would hesitate leaving it on for any length of time until you determine you are not overdriving the LED's.

Which LED set do you have, the 65 inch has two versions, a 16 and a 12 strip? I am thinking you likely have the 12 strip.

I think you can simplify it like this, excepting that oddball version with 16 strips. Assuming each LED drops about 3.2 volts

E60 has 50 total LED's / 10 control = 5 x 3.2V = 16V
E65 has 72 total LED's / 12 control = 6 x 3.2V = 19.2V
E70 has 108 total LED's / 12 control = 9 x 3.2V = 28.8V

So, you need to measure the LED + voltage on the Power Supply. I am thinking if you have 27 volts you are not only stressing the LED's, but also the MOSFET controllers on the main board.

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

So I did a quick scan over at shopjimmy and it looks like there are resistor differences around U301 the LED controller, but the biggest problem is T301 looks to be a different P/N, which really makes sense as a way to get a higher voltage.

I also see the issue on Ebay and the quite pricey Power Supply availability.

I still have the 60 inch here and can take measurements if need be. I think they are close enough to get good vs bad numbers.

[alfatv]

Re: Vizio E65-E3 Dead after backlight replacement

So I did a quick scan over at shopjimmy and it looks like there are resistor differences around U301 the LED controller, but the biggest problem is T301 looks to be a different P/N, which really makes sense as a way to get a higher voltage.

I guess those could be swapped.

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

it is the 12 strip..6 leds per strip....voltage measured is 57.5v

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

it is the 12 strip..6 leds per strip....voltage measured is 57.5v

Well so much for simplifying it as I thought you would get in the neighborhood of 28V with the 70 inch Power Supply. It's almost like they have 6V LED's or I don't understand how they are arranged. I do recall you testing the LED's with the DMM and getting a reading, and that's not going to happen if you have 6V LED's.

I guess another way to ballpark it is what do you read when testing the LED's with the LED tester?

That voltage should be near the required output of the Power Supply. For example on the 60 inch the strips test at 13.5V (5 LED's), but the Power Supply is outputting 16.5V, which gives it plenty of headroom for the extra drop at higher currents and for control while keeping the power waste at a minimum.

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

ok i swapped t301 and the resistors around u301....now voltage to leds is 49.3
powering one strip with the tester shows 32.4 v

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

ok i swapped t301 and the resistors around u301....now voltage to leds is 49.3
powering one strip with the tester shows 32.4 v

Around U301, electronics is about details so that is a bit iffy :-)

So that 32.4V is powering one strip or 6 LED's, is that correct?

If so, then those would be 6V LED's, which I am a bit confused on as earlier you indicated you could slightly illuminate them with the DMM checking one at a time.

Sidebar: a bit of extra reading and it appears there are DMM's out there that will output as much as 7 volts in the diode mode, which is new to me. Perhaps that is what your meter is doing. Can you share the brand and model number?

Anyways, I would not have recommended going the route of changing the transformer, but that is because I would not suggest making changes to someone else's equipment where it might be difficult to verify the safety of the end product - does it meet original parameters and current limit and shut down as originally designed?

That said, I would suspect that you are in a much safer place now but the voltage still seems a bit high if 6 x nominal 6.2V = 37.2V. That would mean about 12V of excess voltage for the strips.

[alfatv]

Re: Vizio E65-E3 Dead after backlight replacement

ok i swapped t301 and the resistors around u301....now voltage to leds is 49.3
powering one strip with the tester shows 32.4 v

Can you connect all strips and see if you have same issue as before?

[RDC55]

Re: Vizio E65-E3 Dead after backlight replacement

Can you connect all strips and see if you have same issue as before?

He could but he might be stressing components, and I am by no means sure, but use this logic.

The original 70 inch board was outputting 57.5 volts. The 70 inch has 9 LED's per strip or 9 x nominal 6.2V = 55.8V. That seems very reasonable.

So, the 65 inch has the 6 LED's per strip or 6 x nominal 6.2V = 37.2V. The last measured voltage of 49.3 seems like it is too high and there is something being missed in the comparison of the two boards.

[alfatv]

Re: Vizio E65-E3 Dead after backlight replacement

He could but he might be stressing components, and I am by no means sure, but use this logic.

The original 70 inch board was outputting 57.5 volts. The 70 inch has 9 LED's per strip or 9 x nominal 6.2V = 55.8V. That seems very reasonable.

So, the 65 inch has the 6 LED's per strip or 6 x nominal 6.2V = 37.2V. The last measured voltage of 49.3 seems like it is too high and there is something being missed in the comparison of the two boards.

It's not too high. It needs to be higher than nominal, so mosfets on main board can generate constant current for LEDs.
Also supply voltage to LEDs may drop when all LEDs are connected.

[a460guy]

Re: Vizio E65-E3 Dead after backlight replacement

meter is a Fluke 87v

see post #31 for pics....3 wire connector feeds 2 strips that clip together. red wire goes to both strips....white to 1st strip, black to 2nd.