Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour or so

[Doc38343]

Vizio E500i-B1 - Powers on then fades out. No backlight flash just the led power indicator comes on then fades slowly out.
Now here's the burn, if i unplug it for an hour or longer it will power on like normal and even run all day long, up until I turn it off again. If I leave it plugged in as normal it will not power back on.
Standby voltage 5V normal in both cases, as well as the power on signal, 3.3V when i power it on but the set does not fire up. Unless of course I have had it unplugged for a time.
Also note that the 24V supply going from the power supply to the mainboard works in the case where the set has been unplugged for a while but does not power up when it is plugged in and powered down normally then turned back on.
Any help pointing me in the right direction is appreciated. I wish the board had fully failed it would be easier to find the actual problem.

Thanks!!
Doc

[CapLeaker]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Any hi resolution, straight shot pictures of the main board that you could post?

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Here are pics of the main board and the power supply. Sorry had some trouble getting my dumbazz smart phone to connect to my pc. (something i never had any problem with until today)

[budm]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Can we see the pictures of the whole back side of the TV so we can see how all the boards are connected together? I wonder what that Transformer on the main board is for and the red/black wires on the connector on the main board.
I wonder if it has EEPROM problems.

[dick_barton]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Can you provide the voltages on the connector along with the name for each pin when in standby and when out of standby.

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Here are some additional photos that show connector and voltage markers.
The voltages are spot on when it is powered on after being unplugged so i will not list them they are as marked. I will have to get it into the failed state then i will list the readings in that state in the next post.

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

These are failed state off readings:
top connector: 0.0V all connectors

Right side connector:
Red 5.12 and orange 5.12
NC - NC
Blk 0v and bro 0v this rail is 12v when working
Grey 0v and whi 0v this rail is 24v when working
Blue /Violet 0v ground rail
Yellow /Green 0v ground rail
Red 0v - is 3.3V when working -PS-ON
Blk 0.26v and Brown 0v DW and ON/OFF

These are failed state when trying to power on - pressing power on
Top Connector: reds go to 7.9v then bleeds slowly down to 0v again

Right Side Connector:
Red 5.12 and orange 5.12
NC - NC
Blk 6v and bro 6v then slowly bleeds back to 1.4v and pauses then goes to 0v after 15seconds or so - this rail is 12v when working
Grey 12v and whi 12v peak then bleeds back down same as above - this rail is 24v when working
Blue /Violet 0v ground rail
Yellow /Green 0v ground rail
Red 2.98v and N/C - this on holds for much longer than the 12 and 24v rails is 3.3V when working -PS-ON
Blk 0.26v peak and .06v and Brown 3.3v when I press power first then back to 0v if i press it again. ---DW and ON/OFF

[Diah]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

i have faced this issue before round 4 years ago .. with Philips first smart TV generation, Green led go fade after plug out and in again at short time, all thought go to power supply caps to change them all at secondary stage, but didn't help,, the fault was at the WIFI module just plug it out..

[CapLeaker]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

First we got to figure out what PSon, On/Off and DIM signals do when the TV fails. It's not quite clear how you written it. So just checking...
So what you saying is that you lose PSon in the failed state?
On/Off is the backlight. what does it do when the TV fails? Same for the DIM.

Sounds like an EEPROM going bad or a bad Wifi module, both already have been suggested.

Find the EEPROM on the main board and freeze it with a can of air upside down, turn the tv on and see what happens.

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

OK it is not the wifi - tried it with and without it connected.
ON/OFF signal works correctly at button push.
The PS-on voltage is about .5 v(half a volt) lower when it is in the failed state than when i turn it on after being unplugged.
I believe it is a mosfet or IC that is not switching upon power off and stays on. One of the tiny SMD caps or diodes is likly shorted or something. This is also a known issue with this model tv.
I am just wanting to replace the board as opposed to spending several hours of my precious time trying to find the haystack needle.
My question is therefore:
Most likely board to swap- Power supply or Main board
Seems that the signal going to and coming from the main board is correct, however I am wondering why the PS-ON voltage changes slightly.
and I suspect this may be the reason for the 12/24V rails not starting.
It is obvious that a device is not switching on power off question is which one.

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

UPDATE:
Was very busy earlier so I had it unplugged for 3 hours or so but this time it still will not turn on and the led power indicator lights for a couple of seconds and then just fades out again. (same as when it was left plugged in before)
I have tried it with the WIFI board disconnected, the TCon board disconnected, also the top ribbons that feed the backlights one at a time and both.
SAME results in all cases.
I took the power supply off and checked everything I could on the bottom and top side with no luck. Problem is not obvious. I now suspect the main board may be the culprit. I am not finding any definitive solutions online in searches. I did see a case where a guy said he bought a power supply but it did not fix it.
I really wish folks would follow up and post the solution when they find one. (other sites.. everyone is pretty good on here) Most just stop when it gets fixed or just say they got it without the how it was done. Mostly just finding rants about how crappie Vizio is but I would suggest doing the reviews BEFORE they buy one.
Power supply or main board..... still my dilemma!

[Doc38343]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Just had another thought:
If the on/off is going to 3.3v and the PS-ON is coming up to 3v then what turns on the 12 and 24v rails. Wouldn't that be the failing section? 5v standby is dead on and no fluctuation remote control power on/off works and standby voltagew is right on that little board. Which board starts the 12v/24v rail... I did carefully trace the top 24V connector and it appears to go to the HOT section separate from the 12v/24v on the side connector. I was therefore thinking the main board may be the fail. Reason is the top connector 24v rail is all 4 wires to same rail. it only pulls up to about 8v before falling back down.
The side connector 24v pin pulls all the way to 12v then it falls back down.
I have a nice headache, no schematics and a TV that many people are upset about. LOL
Hope some of this info helps you help me, thanks again!

[budm]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

You can tell if the PS-ON signal is OK or not by checking the DCV between the two legs of the main filter caps (you have two of them and they are connected in parallel), when TV is OFF, the dcv should be around 165VDC, and when the PS-ON signal is present, the dcv should be around 380~400VDC, if you do have that Voltage then the PS-ON signal is fine.
PS-ON is also used to turn on the switched 12V power supply and the switched 24V power supply. The SMPS IC9101 for the 12V/24V runs from the 380V PFC Boosted Voltage through the fusible resistor R9140.
The ON/OFF signal is for backlights ON/OFF.
PS-ON, ON/OFF, DIM signals are generated by the Main board, the PS-ON, ON/OFF usually >2.5V = ON, <1V = OFF.

BTW, there are more than one versions of this TV model.
Which are the boards used in your TV?
http://www.shopjimmy.com/catalogsear...=Vizio+E500i-B

[dick_barton]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Disconnect the power supply from the main board and jumper a 1K resistor from the standby voltage to ON/OFF and a second jumper resistor from standby voltage to PS_ON
and see if it brings up the missing supplies.

[budm]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

BTW, the backlights LED driver circuit is on the main board.

[dick_barton]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

Now here's the burn, if i unplug it for an hour or longer it will power on like normal and even run all day long, up until I turn it off again. If I leave it plugged in as normal it will not power back on.

Hi Budm, Didn't the first post says that after the set has been on for a while and then switched off and back on the supplies are not coming up fully so wouldn't he need to find what is causing this problem.

[budm]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

He needs to check the PS-ON and the PFC Voltage when it fails.
But if he has to unplug the unit for hours for it to work again, that to me is the main board problem.

[dick_barton]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

I see where you are coming from. With everything connected can't he lift the PS_ON pin from the connector and jumper Standby to PS_ON pin to confirm whether or not the mainboard is the problem?

[budm]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

I see where you are coming from. With everything connected can't he lift the PS_ON pin from the connector and jumper Standby to PS_ON pin to confirm whether or not the mainboard is the problem?

He can do that too.

[Diah]

Re: Vizio E500i-B1 - Powers on then fades out - Works if left unplugged for an hour o

UPDATE:I had it unplugged for 3 hours or so but this time it still will not turn on and the led power indicator lights for a couple of seconds and then just fades out again. (same as when it was left plugged in before)
I have tried it with the WIFI board disconnected, the TCon board disconnected, also the top ribbons that feed the backlight!

its time for you to invest little $ to have Freeze spray to cool caps or IC on main boards first